Global

Electrical grid and appliances: schemes to make them work together

2025-12-18T08:00:18Z

Note: this post is an update of the post Interoperability of smart appliances in the EU

Smart appliances and interoperability

Electricity from renewables, accounting for a growing portion of the grid, is not constant and may not always match demand; consequently, so-called smart strategies to keep electrical appliances/equipment functioning are being developed and will likely be implemented in the near future.

A smart appliance is an appliance that controls its energy consumption through demand-side flexibility¹:

It is able to automatically respond to external stimuli, e.g. tariff information, direct control signals, and/or local measurement (mainly voltage and frequency).
Its response is a change in the appliance’s electricity consumption pattern (demand response). These changes to the consumption pattern are referred to as the “flexibility” of a smart appliance.

Excerpt from Figure 8 of “Unlocking flexibility: No-regret actions to remove barriers to demand response 2025 Monitoring Report“, ACER, 9 April 2025

Communication between the electrical grid and the connected appliances, as well as between the appliances themselves if they need to be aggregated to augment overall flexibility, is called interoperability: “Interoperability is understood as the communication and data exchange link between the individual appliance and the supply side … via a home energy manager or internet/cloud systems and in some cases also the AMI (Advanced Metering Infrastructure), making it possible to achieve a better balancing of energy generation and energy consumption within the grid and/or to avoid grid congestion.”² The device’s capability to measure the power grid’s parameters (i.e., voltage and frequency) can also be added to this definition.

Interoperability schemes in the EU

As of now, there are three main interoperability schemes in Europe³:

The Code of Conduct for Energy Smart Appliances (CoC ESA):
- Code of Conduct v.1.0, available since 23 April 2023, is a voluntary scheme that defines the structure of the exchanged data⁴ and the characteristics of the communication protocol⁵, without advocating for any protocol in particular. Ver. 1.0 covers white goods (washing machines, tumble driers, washer-driers, dishwashers), and HVAC appliances (including water heating). Adhering manufacturers are prominent manufacturers of white goods and HVAC products for the domestic and small-commercial markets.
- CoC v. 2.0, currently under development, was launched on 18 September 2024 to add new devices: energy management systems (EMS), photovoltaic inverters (PVI), and electrical vehicle chargers (EVC).
ACER Recommendation 01-2025 on reasoned proposal for the establishment of the network code on demand response:
- Annex 4a proposes amendments to Regulation (EU) 2016/1388 on the DC Network Code on Demand Connection (NCDC). The Regulation defines “a network code which lays down the requirements for grid connection of … heat pumps ...”, among other devices (art. 1).
- If the proposal passes, heat pumps, newly added to the NCDC, will need to self-measure the grid frequency and reduce, according to a defined pattern, their electricity consumption if the frequency decreases below a certain threshold.
UK Smart Secure Electricity Systems (SSES) Programme:
- The Smart Secure Electricity Systems (SSES) Programme creates the technical and regulatory frameworks to help consumers access cheaper electricity.
- If approved by the UK Parliament, from 2027, domestic scale heat pumps will be required to have demand-side flexibility capabilities⁶ in order to be placed on the market. Such capabilities shall be present in heat pumps, but it will be up to the user to activate them.
- In addition, if Parliament approves, from 2030, domestic scale heat pumps will be required to react to time-of-use tariff signals from the grid and/or to be directly controlled by the grid, de facto conceding full flexibility, for which the heat pump owner will be remunerated. Again, such capabilities shall be present in heat pumps, but it will be up to the user to activate them.

Consequences on products and equipment

It seems clear then that although these three schemes are aimed at the same target, i.e. demand-side flexibility, they are not equivalent to each other: the CoC ESA involves interoperability hardware and software upgrades for heat pumps; the ACER Recommendation requires hardware and software upgrades to self-modulate heat pump electricity consumption based on the grid’s frequency, and not for interoperability; finally, the UK SSES sets a framework for demand-side capabilities, but different from those defined in the CoC ESA.

In all cases, upgrades of heat pumps are required, with the possibility that such upgrades might not be feasible either because the changes entail disproportionate costs or because some heat pumps may be too obsolete to make them possible, with the consequence of requiring investments in innovation by manufacturers. On top of this, the diversity of the schemes is also an implicit cost if they need to be differentiated per market.

Hopefully, there will be some degree of convergence to avoid differentiation of products based on their geographic destination, which would go against the concept of market harmonisation, and require too many concurrent product upgrades.

Stay tuned for the next steps!

References:

¹. Based on sect. 7.1 “Definitions” of “Preparatory study on Smart Appliances (Lot 33) - TASK 7 REPORT – POLICY AND SCENARIO ANALYSIS”.
². Excerpt from sect. 3.1 of “Energy Smart Appliances’ Interoperability: Analysis on Data Exchange from State-of-the-art Use Cases” by Papaioannou Ioulia, Andreadou Nikoleta, Tarramera Gisbert Angel; EUR (where available), Publications Office of the European Union, Luxembourg, 2022.
³. There are a couple of other schemes valid at a national level but they are not covered in this post.
⁴. Fully compliant with the SAREF framework of ontologies according to technical specification ETSI TS 103 264 (SAREF core) and ETSI TS 103 410 series (SAREF extensions).
⁵. Open Application Programming Interface/Open Communication Protocol as per, for instance, EN 50631:2023.
⁶. As defined by “PAS 1878:2021Energy smart appliances –System functionality and architecture – Specification”.

Let’s talk about IoT: are all smart appliances really smart?

Interoperability of smart appliances in the EU

From humidity to heat recovery: smart control solutions for energy-efficient paint booths

2025-12-11T08:00:17Z

Following on from my previous article, where I explored the importance of integrated control systems in managing fan speed, temperature and humidity to optimise paint booth performance, we now turn our attention to three advanced technologies that further enhance environmental control and energy efficiency.
In this second part, I take a closer look at adiabatic humidification, evaporative cooling and heat recovery examining how their correct integration into the control logic can bring substantial energy savings without compromising process quality.

Adiabatic humidification

Adiabatic humidification lowers the air temperature, and therefore temperature-humidity control needs to consider the link between the two variables: to maintain the set point in paint the booth, as the flow-rate of moisture transferred to the air stream increases, preheating also needs to be increased. To limit swings in temperature due to humidification, the most effective humidifier control method is based on absolute humidity (amount of water vapour present in 1 kg of air, measured in grams per kilogram of dry air). In fact, unlike relative humidity, absolute humidity does not vary as a function of temperature.

At the same time, temperature-humidity control also needs to take into account the fact that the effectiveness of the humidification process is influenced by the conditions of the incoming air stream. Cold air does not have the energy needed to evaporate and absorb moisture. The result is that large amounts of water are needed to transfer small quantities of moisture to the air. The air therefore needs to be preheated, both to offset the drop in temperature and to guarantee high water absorption efficiency. A typical control system uses a temperature probe installed after the heating coil, called a “saturation probe”, and works to bring the temperature to an adequate level to ensure absorption. Sometimes additional heating may be needed downstream of the humidifier to reach the desired temperature value. This occurs with wetted media systems: given the inertia of the evaporating matrix, wetted media humidifiers do not allow humidity production to be modulated quickly, and therefore require the air downstream of the humidifier to be reheated, so as to avoid unwanted temperature swings.

The use of variable-speed adiabatic atomisers allows very precise control of the conditions downstream of the humidifier, based on the saturation temperature reading or, even more effectively, measuring the air temperature and humidity downstream of the air preheating coil, and trying to reach the enthalpy of the desired set point. Adiabatic humidification is an isenthalpic transformation and therefore, starting from a point with the correct preheating temperature and the same enthalpy as the end point, the set point conditions can be reached and maintained with the highest precision, by continuously varying the flow-rate of atomised water.

Example of enthalpy-based preheating control with preheating only

In principle, by having modulating actuators available and setting the controller correctly, preheating can be controlled using the temperature probe downstream of the humidifier: higher humidification demand brings about a drop in temperature that the heating coil needs to offset. In this case, the responsiveness of the controller must be consistent with the inertia of the devices: if the valve on the heating coil takes two minutes to complete its travel but the humidifier can respond in just a few seconds, when the humidifier is activated there will be a sudden increase in relative humidity and drop in temperature, thus failing to reach the set point. It is therefore important to use the PID values, for example, setting a lower proportional constant for the humidifier, and then acting on the integral value to ensure more stable control and avoid swings.

Evaporative cooling

Direct evaporative cooling (DEC) can be used on the incoming air supplied to the paint booth. It is only possible if the incoming relative humidity does not exceed the limit values for the process, usually around 80% RH. In this case control uses a temperature probe, usually together with a humidity limit probe to avoid high values (>80% RH) that could lead to condensation in the ducts or paint defects. The use of modulating humidifiers allows optimised control: humidifier operation is modulated based on the cooling requirements and the humidity limit, reducing production and allowing cooling to be delivered by other devices. In this case, it is very important to ensure that the cooling device does not dehumidify the air: removing the moisture previously added to the air stream is in fact a waste of energy. Therefore, when dehumidification occurs, the controller must stop the evaporative cooling system.

Typically, in temperate climates, cooling is often associated with latent loads, and therefore humidity needs to be lowered rather than increased. In painting processes, where the optimal relative humidity level required is quite high, direct evaporative cooling (DEC) can be advantageous, pushing the humidity to the maximum limit to take advantage of its free cooling effect.

Alternatively, evaporative cooling can be used to cool the exhaust air entering the heat recovery unit, consequently bringing about a drop in the supply temperature without affecting the humidity. This process is called indirect evaporative cooling (IEC).

Adiabatic humidification and evaporative cooling (DEC+IEC) layout using a single humidifier pumping station

Heat recovery

The various heat recovery technologies examined here differ in terms of the possibility of modulating operation and the type of heat recovered, whether sensible or sensible plus latent. From a control point of view, a heat recovery unit behaves just like a heating or cooling device, with possible dehumidification. Modulation is managed with appropriate ON/OFF or modulating outputs that control bypass dampers (modulating or ON/OFF), rotation speed (for thermal wheels), or the fluid flow-rate in a run-around coil system. More specific additional functions are available for heat recovery units, which vary in complexity depending on the devices and the inputs and outputs available.

The criterion for activating a heat recovery unit is normally based on a temperature differential between the outside air and the extracted air. This temperature difference gives an idea of the energy that can be potentially recovered by the heat exchanger, which must then be compared against the energy required to make the heat recovery system work, whether the power consumption of the motor that drives a thermal wheel or the pump on a run-around coil system, as well as the energy consumed by the fans to overcome the extra pressure drop due to the heat exchanger being placed in the air stream. If the temperature difference is not sufficient, the energy recovered is less than that consumed by the fans to overcome the pressure drop, and therefore it is more cost-effective to bypass the heat recovery unit, using the bypass dampers. Normally, the heat recovery unit activation temperature differential is defined during the design phase, and is generally set at around 1-2°C.

The bypass is very useful in winter, when cold temperatures can lead to condensation and consequently ice forming inside the heat recovery unit. The cold air bypass allows only the hot air leaving the paint booth to flow through the heat recovery unit, and this melts any ice that has formed. The bypass can be activated based on temperature or pressure, using, for example: thermostats installed in specific positions in the heat recovery unit, temperature probes that measure heat exchanger efficiency, temperature and humidity probes upstream and downstream of the heat exchanger, and differential pressure probes that check for pressure drop, which change significantly when there is ice blocking the channels. There are various possible control strategies, and these depend on the probes available: the most common are based on time or on measuring the exhaust temperature, which tends to rise once the heat recovery unit has been defrosted. It is clear that sophisticated logic requires microprocessor controllers with the ability to compare the readings of multiple sensors and store data.

Crossflow plate heat exchanger with central bypass section and dampers

Unlike plate heat exchangers, thermal wheels have different auxiliary logic, normally managed by a specific controller. In addition to defrosting as described above, a thermal wheel also needs to manage feedback on rotation of the drum (often via a pulse signal), for example to check for problems with the drive belt. Another additional control function is “rotation due to inactivity”, activated when the heat recovery unit remains off for an extended time, to prevent the wheel from deforming due to its own weight while always remaining in the same position.

Crossflow plate heat exchanger with central bypass section and dampers

The control of heat recovery when indirect evaporative cooling is used is also worth looking at briefly. Evaporative cooling involves using a different activation threshold for the heat recovery unit: heat recovery conditions that are not cost effective due to a temperature differential that is too low, as described previously, could actually become cost-effective if evaporative cooling is activated. Activation of the heat recovery unit and the evaporative cooling system need to be evaluated based on various cost-effectiveness parameters, above all the cost of energy and the cost of water.

The topics covered in this blog post about humidity and temperature in painting booths are explored in detail
in the white paper “Highly-efficient solutions for painting – Humidity, temperature and heat recovery control”.

Download the white paper

How to turn control into value

2025-12-04T08:00:18Z

For a company, being listed on the stock exchange is major step that goes well beyond opening its capital to the market. It involves new dimensions in terms of responsibility, transparency, and management complexity, requiring a review of the organisational structure and, in particular, corporate governance.

Corporate governance is often thought of simply relating to board members and their strategic decisions. But, as the Italian stock exchange’s definition stresses, corporate governance represents “the set of tools, rules, and mechanisms designed to best implement a company’s decision-making process in the interests of the different stakeholders involved in the business.” In other words, governance is a complex ecosystem that not only includes the Board of Directors and the executive and audit committees, but also corporate policies, decision-making processes, tools and internal controls and auditing systems. It is how, in practical terms, responsibility is shared, transparency mechanisms are created, and trust is built with all stakeholders: investors, employees, customers, suppliers, and local communities.

For companies making the transition to being listed, this paradigm shift is fundamental. Listing brings with it strict regulatory requirements, from the CONSOB (Italian financial conduct authority) issuer’s regulations to international standards. These however should not only be considered as formal requirements, but rather also as opportunities to establish more robust processes, strengthen corporate culture, and manage change responsibly. Governance requires distinct roles, complementary skills, and a system designed to ensure transparency, solidity, and long-term vision. Together with the Board of Directors, there are supervisory bodies that monitor the correctness of management processes, while other specialised committees deal with auditing, risk management, sustainability, and remuneration policies.

Corporate governance roles, adapted from Dittmeier, “Internal Auditing”, Egea 2011

In this context, the Internal Audit function is an important part of the governance system. Too often perceived as having a mere supervisory role, the Internal Audit function actually plays a strategic role in creating value. It assesses the adequacy, effectiveness, and efficiency of internal auditing and risk management systems, providing assurance services to confirm to both management and external stakeholders that the organisation is operating correctly, ethically, and sustainably. Through advisory services, it also supports the company in identifying improvement opportunities and implementing more efficient auditing systems.

The Internal Audit function’s ability to generate value is demonstrated through some fundamental practices, which are particularly relevant for recently-listed companies. However to be effective it cannot operate in isolation: its strategy needs to be aligned with the overall corporate strategy. This means developing an audit plan based on the highest-priority risks that may hinder the achievement of strategic objectives. Integration with enterprise risk management allows audits to be focused on the areas of greatest strategic importance, making a concrete contribution to protecting and creating business value. The most effective functions are those that coordinate activities with other internal and external assurance providers, providing the Board of Directors with a holistic overview of corporate risks. This integrated approach strengthens the position of the function and increases its perceived effectiveness.

Continuous interaction with the Risk Control Committee, top management and subjects being audited is essential. When Internal Audit responds to the needs of top management, for example by verifying regulatory compliance in sensitive areas, it prevents risks that could otherwise result in fines or reputational damage, thus safeguarding corporate value. At the same time, by involving the audited subjects, for example through interviews, listening to their difficulties and suggestions, it creates a virtuous cycle of collaboration and continuous improvement. In a context where sustainability represents a strategic imperative for organisations, an Internal Audit function that includes checks on environmental, social and governance aspects can provide independent guarantees that the company is operating responsibly, strengthening transparency and generating concrete benefits for the community.

For listed companies, well-structured corporate governance and an effective Internal Audit function are not only regulatory obligations, but also real drivers of competitiveness. An audit culture becomes a competitive advantage, building trust with the market, boosting the company’s reputation and ensuring long-term business continuity. In an increasingly complex and regulated environment, investing in these areas means investing in the sustainability of the company itself.

The hidden chemicals in the indoor air we breathe: understanding VOCs

2025-11-27T08:00:16Z

Most people think of air pollution as something that happens outside, near factories, highways, or in big cities. But here’s the surprising truth: we spend around 90% of our time indoors, and the air inside our homes, offices, or classrooms can often be 2 to 5 times more polluted than outdoor air. From sleeping and studying to cooking and working, nearly every part of modern life happens inside buildings. That means indoor air quality directly influences our health, comfort, and performance every single day. When indoor air is clean and fresh, people feel more alert and comfortable, students learn better, workers are more productive and focused, and sick leave and allergies decrease.

The invisible threat: VOCs

Indoor air contains a mix of pollutants that come from everyday sources. The main indoor air pollutants include volatile organic compounds, or VOCs. Volatile organic compounds (VOCs) aren’t a single specific substance, but rather a large group of carbon-based chemicals that are easily emitted at room temperature as gases into the air from products and processes. Exposure to VOCs can cause a range of short-term and chronic health effects, including headaches, eye and respiratory tract irritation, and in some cases, organ toxicity or carcinogenicity. Because there are so many types of VOCs, they are often grouped together and monitored as TVOCs (total volatile organic compounds).

Major indoor VOCs and their key sources & health effects

Formaldehyde (aldehyde):

Released from pressed wood (MDF, particleboard, plywood), urea-formaldehyde resins, insulation, tobacco smoke, and wrinkle-resistant textiles.
Health effects: eye, nose, and throat irritation; classified as a known human carcinogen.

Benzene (aromatic hydrocarbon):

Found in tobacco smoke, paints, varnishes, solvents, stored fuels, and adhesives.
Health effects: neurological symptoms, bone marrow suppression, and carcinogenic (linked to leukaemia).

Toluene (aromatic hydrocarbon):

Present in paint thinners, lacquers, varnishes, nail polish removers, adhesives, and air fresheners.
Health effects: fatigue, confusion, and long-term neurological damage.

Xylenes (aromatic hydrocarbons):

Emitted from paints, varnishes, solvents, cleaning agents, and aerosol sprays.
Health effects: dizziness, eye and skin irritation, and potential liver and kidney damage.

Ethylbenzene (aromatic hydrocarbon):

Found in paints, coatings, tobacco smoke, and styrene-based building materials.
Health effects: throat irritation; chronic exposure affects the liver and kidneys.

Styrene (vinyl aromatic compound):

Emitted from plastics, foam insulation, carpets, and office equipment (printers, copiers).
Health effects: mucous membrane irritation; potential carcinogen.

Acetone (ketone):

Present in nail polish removers, paint thinners, and furniture polish.
Health effects: eye and throat irritation; headaches; nervous system effects.

Limonene (terpene):

Found in citrus-scented cleaners, air fresheners, and wax polishes.
Health effects: low toxicity but can form formaldehyde and organic aerosols when reacting with ozone.

Ethanol & isopropanol (alcohols):

Common in disinfectants, sanitisers, and cleaning sprays.
Health effects: respiratory irritation and drowsiness at high concentrations.

Terpenes (α-pinene, β-pinene, limonene):

Released from pine-scented cleaners, air fresheners, and essential oils.
Health effects: can form secondary pollutants such as formaldehyde and fine particles.

Dichlorobenzene (chlorinated aromatic hydrocarbon):

Present in mothballs, air fresheners, and toilet deodorisers.
Health effects: liver and kidney damage; potential carcinogen.

Collectively, these VOCs highlight the complexity of indoor chemical emissions and underscore the importance of source control, product selection, and adequate ventilation to reduce exposure and protect human health.

International guidelines and thresholds for indoor TVOC exposure

Organisation / Country	Guideline / Classification	TVOC Concentration Limit	Equivalent (approx.)	Interpretation / Category	Reference
World Health Organization (WHO) – Regional Office for Europe	Based on comfort and sensory irritation levels	<100–200 ppb	—	Harmless	WHO, 2000
	Based on comfort and sensory irritation levels	200–610 ppb	—	Tolerable only for short-term exposure	WHO, 2000
German Federal Environment Agency (UBA)	Hygienic evaluation bands	≤0.3 mg/m³	≈80 ppb	Hygienically safe	Umweltbundesamt, 2007
		0.3–1 mg/m³	≈80–260 ppb	Still acceptable
		1–3 mg/m³	≈260–780 ppb	Noticeable
		3–10 mg/m³	≈780–2600 ppb	Alarming
		>10 mg/m³	>2600 ppb	Unacceptable
Japan (Ministry of Health, Labor and Welfare – MHLW)	Provisional indoor target value	400 µg/m³	≈100 ppb	Recommended limit for residential settings	MHLW, 2002
China (GB 50325-2010)	National indoor air quality standard	≤0.5 mg/m³	≈130 ppb	Limit for residences, schools, and hospitals	MOHURD, 2010
China (GB 50325-2010)	National indoor air quality standard	≤0.6 mg/m³	≈160 ppb	Limit for offices and public buildings	MOHURD, 2010
United States (EPA)	Operational threshold (not formal standard	500 ppb	≈1.9 mg/m³	Indicator for elevated exposure events	U.S. EPA, 2017

Overall, these guidelines indicate that, while no universal standard exists, indoor TVOC concentrations below approximately 200–500 ppb are generally regarded as acceptable for health and comfort in non-industrial indoor environments.

A closer look: CAREL’s case study

To assess how volatile organic compounds (VOCs) behave under real-world conditions, TVOC concentration data from indoor air quality (IAQ) monitoring at CAREL Industries offices were analysed. The analysis compares the concentration and emission rates of TVOCs between two offices, referred to as Office 1 and Office 2. Office 1 is larger, with a volume of 553.5 m³, while Office 2 is considerably smaller, with a volume of 51.66 m³. Notably, an air freshener emitting fragrance was present in Office 2.

TVOC concentration over a week

The graph illustrates the time variation in TVOC concentrations in two offices (Office 1 and Office 2) from 1 September to 8 September 2025. During working hours, when the ventilation system was operating (grey-shaded areas), both offices had lower and more stable TVOC concentrations, highlighting the effectiveness of ventilation in reducing indoor pollutant levels at the workplace. In contrast, when the ventilation was turned off, TVOC concentrations gradually increased in both offices, with a markedly sharper rise observed in Office 2 due to the use of air freshener fragrances.

On weekdays, during nighttime periods without ventilation, TVOC concentrations exceeded 400 ppb in Office 1 and 1000 ppb in Office 2. Over the weekend, when the offices were unoccupied and ventilation remained off, TVOC levels spiked dramatically, surpassing 1200 ppb in Office 1 and approaching 2400 ppb in Office 2. Overall, Office 2 consistently recorded higher TVOC levels than Office 1, primarily due to emissions from air fresheners, in addition to contributions from furniture, cleaning products, and other sources. The estimated emission rates during non-ventilated periods (at night) ranged from 0.27 to 2.46 mg/min in Office 1 and from 0.62 to 19 mg/min in Office 2.

Ventilation made a significant difference. Once the system resumed operation, TVOC levels dropped below 400 ppb within 25–45 minutes, clearly demonstrating that fresh air is one of the most effective measures against indoor pollution. Maintaining adequate ventilation helps ensure a more comfortable, healthier, and productive working environment. The CAREL case study demonstrates how continuous monitoring and intelligent building systems can help identify hidden pollution sources and optimise ventilation schedules.

Lord Kelvin’s saying, “to measure is to know. If you cannot measure it, you cannot improve it”, perfectly captures the essence of indoor environmental quality (IEQ) monitoring. Measuring IEQ parameters—such as air temperature, humidity, CO₂, particulate matter, and VOCs—provides the necessary data to understand the indoor environment and identify sources of discomfort or health risks. Without continuous and accurate monitoring, it is impossible to detect poor air quality, evaluate the effectiveness of ventilation, or implement targeted improvements. Therefore, IEQ monitoring is fundamental for maintaining healthy, comfortable, and productive indoor spaces, enabling evidence-based decisions that enhance both occupant well-being and building performance.

Healthy air is not a luxury - it’s a necessity for a sustainable indoor environment. By combining data-driven insights with smart control systems and effective ventilation, we can enhance our indoor environmental quality.

References:

China Ministry of Housing and Urban-Rural Development. (2010). Code for indoor environmental pollution control of civil building engineering (GB 50325-2010). Beijing: China Architecture & Building Press.
Ministry of Health, Labour and Welfare [Japan]. (2002). Interim target value for total volatile organic compounds (TVOC) in indoor air. Tokyo: MHLW.
Umweltbundesamt (German Federal Environment Agency). (2007). Hygienic guide values for total volatile organic compounds (TVOC) in indoor air. Dessau-Roßlau, Germany: UBA
U.S. Environmental Protection Agency. (2017). Quality assurance handbook for air pollution measurement systems: Volume I – General procedures. Washington, DC: EPA Office of Air Quality Planning and Standards.
World Health Organization Regional Office for Europe. (2000). Air quality guidelines for Europe (2nd ed.). Copenhagen: WHO Regional Office for Europe. Available at: https://iris.who.int/server/api/core/bitstreams/7107999d-7e53-47aa-90e8-bb1d162ff46e/content

Controlling CO₂ concentration with mechanical ventilation

Particulate matter: health and policy

Pollutants and CO₂: air quality indicators

From HFCs to CO₂: smarter refrigeration for the medical industry

2025-11-20T08:00:17Z

In the medical sector, refrigeration is far more than a convenience, it’s a critical safeguard. Production facilities, warehouses and research laboratories all rely on stable, validated temperature conditions to ensure the integrity of medicines, samples and research materials. Even slight deviations from the set point can have serious consequences.

To protect against risks, installations are often built with 100% redundancy: two fully independent refrigeration systems designed to ensure uninterrupted operation. Yet this very redundancy raises important design questions. Should both systems operate simultaneously? Should one remain in standby, coming into service only when an alarm occurs?

Whatever the configuration, one requirement is essential: temperature stability must always remain within the validated thresholds.

The path from HFCs to natural refrigerants

Historically, medical refrigeration systems were built using HFC (hydrofluorocarbon) refrigerants such as R404A. These synthetic gases offered reliable performance but came with a high global warming potential. As environmental regulations become stricter worldwide, the industry is now rapidly moving towards natural refrigerants, which offer comparable performance with a far lower environmental impact.

The shift to CO₂ systems represents not only a compliance measure but also an opportunity: to rethink the entire refrigeration system design for better energy efficiency, smarter control, and long-term sustainability.

A case from Copenhagen

Pharmacold A/S, a Copenhagen-based refrigeration specialist with decades of experience in the medical sector, was tasked with upgrading a freezer room for a local pharmaceutical company. The original installation, operating on R404A, consisted of two independent condensing units located in a machine room, each with its own control panel.

The design was typical of older-generation systems: a pump-down circuit with thermostatic expansion valves, solenoid valves, and simple on/off temperature control. Ventilation was required to remove heat from the condensers. Efficiency optimisation was minimal, and suction pressure control relied entirely on a low-pressure switch. In short, there was clear potential for improvement.

The project goals were defined as follows:

replace the HFC system with a natural refrigerant alternative;
maintain 100% redundancy with two independent units;
introduce electronic expansion valves for more precise control;
improve energy efficiency while keeping the temperature within ±3 °C of the requested set point. In practice, the current result is actually ±2.5 °C around the set point.

A new design philosophy

The new installation replaced the legacy HFC setup with two high-efficiency CO₂-based systems. Each unit operates independently yet works in harmony to maintain precise temperature control.

One of the main innovations was the redundancy strategy. Instead of relying on a traditional standby system controlled by remote on/off signals, Pharmacold implemented a dual-active configuration:

both systems remain active, but one operates at a slightly offset set point (around +2°C);
the evaporator fans on the standby unit continue running, ensuring uniform air distribution and stable temperatures throughout the room;
a weekly digital changeover switch alternates the lead and lag units, ensuring balanced operating hours and uniform wear;
in the event of a changeover fault, both units automatically revert to the same set point, maintaining uninterrupted operation.

This simple yet robust control logic ensures continuous redundancy without the need for complex supervisory systems, offering temperature stability through design simplicity.

Smarter monitoring and validation

For the medical industry, compliance and traceability are as essential as performance. The system was therefore equipped with dual supervision:

an independent temperature logging system managing high/low alarms and regulatory validation;
a central monitoring platform providing real-time data on compressor operation, defrost cycles and energy performance.

The monitoring system communicates directly with the customer’s building management system (BMS) over TCP/IP, integrating alarms, operating data, and system status. This dual-layer structure ensures regulatory compliance while also delivering valuable insights for optimisation and validation during both standard operation and defrost cycles.

Measurable results

The upgrade produced immediate, measurable improvements:

more stable temperature control, both in steady-state and during defrost cycles;
reduced compressor runtime, thanks to inverter-driven modulation;
lower energy consumption, leading to a reduction in operating costs;
reliable redundancy, with seamless changeover between the two systems.

The result is a future-proof, energy-efficient and regulation-compliant refrigeration system tailored to the strict reliability standards of the medical industry.

A blueprint for the future

This case demonstrates how the transition from HFCs to CO₂-based systems can bring tangible benefits in one of the most critical application sectors. Beyond the environmental advantages of natural refrigerants, the combination of modern control logic, data-driven monitoring and intelligent redundancy delivers significant improvements in efficiency and reliability.

For Pharmacold A/S and its customer, the key takeaway was clear: keep it simple. By focusing on smart yet straightforward design principles, it is possible to achieve validated temperature stability, enhanced energy performance, and long-term sustainability, all essential ingredients in the next generation of medical refrigeration.

Flexible innovation and expertise for building decarbonisation

2025-11-13T08:00:19Z

Digital innovation is increasingly becoming a key driver for the decarbonisation of the existing building stock. Faced with increasingly stringent environmental regulations, which transform energy efficiency from a simple economic advantage into a factor that directly affects the value of a property, technology can make the difference.

The real complexity lies in managing already-constructed buildings, often comprising a wide variety of systems. It is in this scenario that next-generation digital platforms can accelerate decarbonisation pathways. The approach, based on open and flexible software solutions, enables integration with pre-existing systems, avoiding invasive interventions or complex revamping.

Energy efficiency is no longer just a matter of savings: compliance with sustainability regulations has a direct impact on the value of properties. Optimising resources thus becomes a new way to increase value, making buildings more competitive and attractive on the market.

Decarbonisation is achieved above all through improving the efficiency of the existing building stock. Even though new technologies, such as heat pumps, play an important role, the real challenge is to act on already-installed systems, which are often complex and non-uniform. This is the basis of the strategy of purely SaaS hardware-agnostic companies.

The goal is to provide powerful yet simple-to-implement tools, capable of interfacing with existing technologies to monitor, control, and improve consumption. This is an effective response to the need to reduce energy costs, but also an opportunity to comply with new regulations and strengthen the sustainability of the building sector.

The path toward efficiency unfolds in two phases. The first is reporting, with tools such as energy management systems (EMSs) that collect and analyse data from smart meters, BMSs, or APIs, providing a complete overview of consumption. Dashboards and reports enable energy managers and facility managers to define benchmarks and make informed decisions. EMSs are generally compliant with ISO 50001 standards and support ISO 14001 procedures, also proving useful for ESG reporting.

The second phase is active optimisation, supported by SCADA platforms, which make it possible to collect operational data from systems and apply remote control logic. The strength of some of these solutions is indeed their ability to integrate with any system, thanks to a wide range of drivers and protocols, allowing complete management that also includes external data, such as weather conditions or space usage patterns. All this is offered with a user-friendly interface and an online graphic editor for simple and customisable management.

An important aspect to consider to ensure the success of these investments is deep knowledge of the systems and how they work. It is not just about collecting data or applying algorithms, but also about knowing how to interpret the significant parameters for each building, acting in a targeted way to improve performance without compromising comfort. Energy efficiency, in fact, must never come at the expense of occupants’ well-being: only solid applied expertise allows for an effective balance between these two needs.

The commercial building sector (offices, retail, hospitality) is extremely fragmented and diverse. To reach such a heterogeneous market, a key element is the presence of a network of qualified partners—such as system integrators or service companies—capable of adopting digital technologies and translating them into high-value-added solutions for end customers.

Digital innovation represents a concrete response to regulatory compliance and, at the same time, a strategic lever to transform existing buildings into more sustainable and competitive assets. An approach that integrates technology, expertise, and collaboration to accompany the real estate sector in the ecological transition.

Tradition and control: Antica Macelleria Cecchini’s “dream room”

2025-11-06T08:00:20Z

Respect for meat, careful monitoring of the right parameters, and constant supervision: this is how a customised approach has transformed the aging rooms at Antica Macelleria Cecchini in Panzano in Chianti.

The challenge

At the beginning of 2020, with the lockdown bringing operations to a standstill and an aging room full of meat, there was a real risk of the products becoming spoiled. Rather than “force” the pace, the company chose to go back to traditions, yet the help of technology: extending shelf life without accelerating aging, managing both temperature and humidity for longer-lasting quality and less waste.

The technical solution

The Antica Macelleria Cecchini facility includes nine cold rooms where the meat is processed, from when it is received as sides, through to the cutting and packaging of the products sold to restaurants and shops. At the heart of the process are two aging rooms, where the halves are stored for at least 20 days at controlled temperature and humidity, thus reducing their moisture content slowly and uniformly, without the formation of a surface “crust” that would block evaporation from the core.
To ensure stable and repeatable conditions, the installer Merenti Refrigerazione created an integrated aging room control system that coordinates cooling, dehumidification and reheating, working in sync with the evaporator to allow natural dehumidification. The control logic manages the two key parameters (T and RH) in combination, based on a series of temperature and humidity probe readings. System management includes defrosting and ventilation, as well as reading condensing unit alarms, so that all the information is available directly on the aging room control panel.
To stabilise the ambient conditions when loading the aging room, special probes measure the temperature of the incoming sides: the controller thus automatically adjusts the set point when warmer goods enter the room, keeping both temperature and humidity stable. An electronic expansion valve allows tighter control of the refrigerant circuit and therefore better product preservation quality.

Local and remote supervision

In addition to control in the field, the solution also includes a central supervisor for medium-sized systems, with local and remote access. Alarms are sent in real time via instant messaging to both company and outside personnel, who can troubleshoot the system and plan maintenance even from hundreds of kilometres away. The architecture connects the two sites located on opposite sides of the road, integrating both the historic facility and the new extension via serial lines and gateways, with secure connections for complete monitoring.

The results for Antica Macelleria Cecchini

System sizing, installation, and fine-tuning to the creation of what Dario Cecchini calls a “dream room”: a system built to meet the real needs of the process; not a standard solution, but rather a system tailored to the company’s philosophy.
The results obtained include:

Superior and consistent quality: stable temperature and humidity conditions throughout the aging cycle, with regular and uniform dehumidification profiles.
Longer shelf life and less waste: longer shelf life and less spoilage, in line with the “zero waste” philosophy that values every part of the animal.
Repeatable processes: control that adapts to the load (new halves) without sudden swings, ensuring the aging process is not excessively “sped up”.
Operational efficiency: faster supervision and response to alarms, scheduled maintenance, and less unexpected downtime.

In the artisan’s own words

For Dario Cecchini, tradition means successful innovation: the goal is not to reduce aging times, but rather to “respect the meat” and improve its taste and smell with a longer and gentler aging process, even at the cost of weight loss that doesn’t maximise short-term profit.
When control and supervision are designed around the product (and not the other way around), technology ceases to be an “end” and rather becomes a means to get the job done better. This is how excellent artisan processes find new life: not by leaving aside tradition, but rather by making it measurable, stable, and repeatable.

The contents of this blog post can be examined more in depth by reading the success story "Antica Macelleria Cecchini: respecting meat and preserving its quality"

Read the success story

A success story of natural refrigerants on industrial pastry

Smart refrigeration: how Studio54 cut energy use and boosted food preservation

Efficiency and precision for an artisan product of excellence

A successful case of variable-capacity compressor management

A success story of natural refrigerants on industrial pastry

2025-10-30T08:00:21Z

Pasticceria Veneta, located in Venice province, stands out for its focus on quality and tradition, along with its dedication to innovation and sustainability. With the expansion of its product range, including gluten-free and vegan options, and the need to reduce energy consumption and environmental impact, the company sought an advanced refrigeration management solution based on natural refrigerants and high efficiency refrigeration technologies.

The choice was part of a green transition of its systems, with the aim of creating a “future-proof” facility. Rather than seeking immediate economic return, the decision was driven by the desire to comply with European environmental regulations and invest in sustainable, long-term solutions. The adoption of natural refrigerants, in particular carbon dioxide (R-744, CO₂) and DC inverter technologies, represents a strategic investment to ensure energy efficiency, reduce environmental impact, and build a modern, flexible system that meets future standards in the food and industrial refrigeration sectors.

Better steady than cold

One of the critical stages in industrial pastry production is preserving the quality of frozen products to avoid changes in consistency, flavour, and aroma. For this stage, two cold rooms are used, each with a volume of 500 m³, allowing products to be stored at a temperature of -20 °C.

Frozen pastry quality depends less on the exact conservation temperature/humidity values and more on how steady these values remain.

When temperature drifts up and down, tiny ice crystals melt and refreeze into larger ones; this is called “recrystallisation”. These larger crystals act like little chisels: they rough up the laminated layers, weaken the gluten, and make creams feel grainy. Studies show that cycling around -15°C by about ±5°C can do more harm than holding a slightly colder or even warmer constant temperature (e.g. above -10°C), because every upward swing triggers micro-defrosts that rearrange the water and fat content. Keeping products at or below -18 °C with minimal swings, and avoiding “softening” transition zones where mobility increases, is the best choice. For those who are curious and want a deeper overview of these mechanisms, see this study.

Humidity plays its own game in the background as well. In a low relative humidity environment, with medium/fast airflows, the surface ice on the products sublimates (goes straight from ice to vapour). The result is so called “freezer burn”: pale, dry patches and measurable weight loss. On the other hand, high humidity leads to moisture condensation on packages and products. This moisture later refreezes as frost, causing clumping and dull surfaces. Multi-component products (e.g., chocolate-coated pastries) suffer from moisture migration: water moves from wetter fillings into drier coatings, reducing snap and fostering sugar/fat bloom. Industry guidance for frozen cold rooms typically sets relative humidity targets of around 60–70% to both limit dehydration and frost build-up, together with sensible (not excessive) air velocities and limited door openings.

For specific bakery products, cold-chain manuals identify frozen dough and cream-filled pastries as being especially sensitive to temperature fluctuations, particularly above -18°C. Controlled “freeze-defrost” tests show hardness increases and springiness drops when products experience this kind of cycling.

In short: steady temperature + steady humidity ensure smaller crystals, intact structures, and flavours that are as true and exquisite as expected.

The natural solution

Temperature control in the cold rooms is ensured by two evaporators, each equipped with an electronic expansion valve managed by two advanced electronic controllers. These feature fine-tuning algorithms for all process variables, a user interface connected to mobile devices such as smartphones, and connectivity to the remote management and data monitoring system. Using the two controllers in combination made it possible to sequence the activation of the two evaporators based on temperature differentials and each unit’s runtime, increasing uniformity and reducing temperature fluctuations inside the rooms.

At the heart of the refrigeration system are high-efficiency units that use CO₂ as the refrigerant. This choice provides both long-term reliability and efficiency. In fact, CO₂ offers excellent energy transfer capacity and very low pressure (and efficiency) losses along the piping to the rooms, delivering high efficiency especially at low-temperature operating conditions, as in this case. Furthermore, being a natural fluid, CO₂ is not affected by any restrictions in terms of use, phase outs or bans, as is currently happening with most synthetic refrigerants worldwide. This makes the choice sustainable for both business continuity and the environment.

Extending system control and efficiency even further is the use of DC inverter compression technology, which couples a sophisticated electronic controller - the so called “drive” or inverter - with a permanent-magnet compressor. This enables precise modulation of the system’s cooling capacity, from maximum demand during rapid cooling cycles down to the minimum during storage - without any wasted energy -while maintaining tight control of storage temperature and humidity.

As can be easily imagined, the modulation capability of the compressor, expansion valves and evaporators plays a fundamental role in keeping both temperature and humidity stable in each cold room. On one hand, activation of the two evaporators can quickly change cooling capacity when needed. Expansion valve modulation is how the capacity of each evaporator is adapted to match the temperature set point and reduce local fluctuations. Furthermore, the expansion valves can modulate their opening to reduce cold room humidity (for example, after opening the door) by smoothly decreasing the evaporation temperature and increasing the dehumidification process. Finally, the compressors modulate their cooling capacity to adapt to the different working conditions and increase efficiency.

Completing the solution is connectivity to remote data-collection, monitoring, and management systems, which provides fully automated, comprehensive control of system performance and enables prompt, targeted service - even via remote - thanks to the detailed information produced by the monitoring system.

A work of art

Pasticceria Veneta has achieved:

Improved product quality through precise control of cold room temperature and humidity, ensuring optimal product preservation.
Green transition and system sustainability by adopting CO₂ (R-744) as the refrigerant.
Energy savings due to a 30% reduction in electricity consumption.
Operational efficiency thanks to remote management and continuous monitoring, which improved the responsiveness of service and system maintenance.

The contents of this blog post can be examined more in depth by reading the success story "Pasticceria Veneta - A system that revolutionises the preservation of pastries with efficiency, control, and environmental responsibility"

Read the success story

Smart refrigeration: how Studio54 cut energy use and boosted food preservation

Efficiency and precision for an artisan product of excellence

A successful case of variable-capacity compressor management

Lean and artificial intelligence: synergy to increase efficiency and quality, with both opportunities and risks

2025-10-23T07:00:20Z

Integrating artificial intelligence to support lean principles is a lever for both transforming manufacturing processes and improving efficiency and quality, however it requires a structured approach that combines technological innovation and methodological rigour.

What is artificial intelligence: its foundations and evolution

The birth of artificial intelligence dates back to the 1950s, when a number of pioneers began wondering whether a machine could actually “think”. One of the first was Alan Turing, with his famous test, while in 1956, at the Dartmouth conference, John McCarthy coined the term “artificial intelligence”.

The first systems were based on very rigid logical rules: perfect for mathematics, yet not really useful for dealing with more complex situations. In the 1980s, new impetus came from artificial neural networks, inspired by the functioning of the human brain and capable of simulating more flexible learning processes.

In the early 2000s, with the boom in big data and the increase in computing power, machine learning and, subsequently, deep learning began to be developed: techniques that made it possible for machines to learn from data and evolve over time.

We are now in the era of generative AI, which is not limited to analysing massive amounts of data, but rather is capable of generating different types of content.

Lean and AI: practical approaches and technology

The aim of lean philosophy is to reduce waste, value people, and achieve continuous improvement. Artificial intelligence, on the other hand, offers the possibility to process enormous amounts of data in real time, recognising patterns or signals that may otherwise not be picked up by humans. Integrating these two approaches offers the opportunity to develop more efficient and flexible production systems.

A number of studies have highlighted the potential benefits of integrating AI and lean:

Optimised resource management: AI facilitates the effective allocation of production resources, quickly adapting capacity and materials based on varying demand and operational priorities. This improves flexibility and reduces waste and downtime.
Predictive maintenance: by analysing data from sensors and machinery, AI can anticipate failures or anomalies before they cause machine downtime. This means targeted service can be planned, reducing downtime and extending the working life of the equipment.
Faster and more accurate decisions: by generating insights based on company data, AI enhances decision-making, helping identify critical issues, manage actions, and optimise resources effectively.

Artificial intelligence makes data a strategic asset for continuous improvement, helping identify the key to reducing waste, delays, and inefficiencies in business processes.

Risks and threats of adopting AI

While offering numerous advantages, adopting AI in lean processes does involve certain critical issues that, if not managed carefully, can jeopardise the success of the project:

Data quality: AI models are extremely sensitive to the quality of the data they are trained on. Noisy, incomplete, or inconsistent data can lead to incorrect predictions or the inability to detect anomalies.
Cultural resistance: in many manufacturing environments, AI is seen as a “black box” or a threat. This can lead to mistrust and slow down adoption, especially if there is no active staff training and engagement.
Self-referential models: AI learns from historical data and therefore can easily replicate biases, inefficiencies, or mistakes from the past. If left unchecked, these mechanisms reduce AI’s ability to drive meaningful continuous improvement.
Inconsistent outputs (“hallucinations”): some models, particularly generative AI, can produce results that are incorrect or out-of-context. To avoid making the wrong decisions, it is essential to always maintain human control and adopt rigorous validation.
Technological dependence: the excessive use of AI can reduce people’s autonomy, delegating too much power to technology. The risk is that the flexibility and problem-solving ability underlying lean thinking will be lost.

An effective roadmap for sustainably integrating AI and lean

Integrating artificial intelligence into lean processes requires a gradual and structured approach centred around people, data, and technology. Effective implementation can be divided into several phases:

Clearly map processes: a thorough understanding of activities is needed to identify where AI can generate real value, avoiding superficial or misaligned actions.
Ensure data quality and availability: it is essential to collect as much data as possible. Data cleansing is equally important, though, as without a reliable database, even the most advanced algorithm will fail.
Involve people from the outset: change cannot be imposed from above. Training and feedback are needed so that AI can be perceived as a support tool and not a threat.
Initiate pilot schemes: start with limited but meaningful use cases, measuring the benefits and building internal know-how around the use of the technology, so as to gain trust in the technology.
Integrate AI into the lean PDCA cycle: the introduction of AI also needs to follow the iterative logic of the Plan-Do-Check-Act cycle, adapting to the results and feedback it receives as inputs.
Update models: AI is not static, and the models need to be updated over time to maintain expected performance.
Promote human-machine collaboration: the goal is not to replace human thought, but rather to support it. AI supports the ability to observe, analyse, and improve, aspects that are typical of a lean mindset.

Conclusions

The integration of artificial intelligence into lean contexts is a real opportunity to improve the efficiency, quality, and responsiveness of manufacturing processes. However, technology on its own is not enough: AI is a powerful resource that requires a conscious and structured approach, becoming a tool that serves processes and people, and not vice versa.

References:

¹. https://retrocausal.ai/blog/how-ai-is-shaping-the-future-of-lean-manufacturing/
². https://amfg.ai/2024/01/22/unlocking-the-synergy-between-ai-and-lean-manufacturing/

Fault simulation in heat pumps with propane (part 2)

2025-10-16T07:00:18Z

In the first part, we presented a detailed overview of heat pump operation, highlighting the impact of anomalies on system performance and energy efficiency. We developed and validated a dynamic simulation model of a domestic air-to-water heat pump, demonstrating its ability to accurately reproduce real operating conditions. This model served as a solid foundation to explore fault scenarios without the time and resource constraints of laboratory testing.

Synthetic data generation

Since we have a reliable model available for simulations, we can use it to generate various dataset, including anomalous conditions. In fact, by tuning some components, we can replicate the fault in the real machine.
In detail, we can simulate fouling in heat exchangers, compressor inefficiencies, pressure drops, bad components control and sensor faults. We will focus on the evaporator fouling, since we can compare it with some real results acquired in the laboratory, the evaporator is a finned coil heat exchanger.
The most common fault occurring in the evaporator is the dust and dirt covering it, causing an evaporator fouling (EF). The component gives us the possibility to modify a parameter called “fouling factor”, who is low in the healthy case, while it is higher in a case of light fault and medium-high fouling. The main effects of EF on the functioning are visible on a sensible reduction of the evaporation temperature and a smaller evaporation pressure. As side effects, to mitigate the problem, the compressor increases its rps (revolutions per seconds), causing an increment of the discharge temperature and pressure, all causing an increment of the electrical energy consumption, reducing the COP.

Comparison with real data

In this chapter we will present the differences/similarities between the model and the real data. In Table 2 reports for a single operating point, all the records (measured and derived) collected using the acquisition system.

Table 2. Comparison of real data and simulated data for healthy and evaporator fouling. the tests are all in stable conditions, with fixed thermal load (the same of the previous chapter) and fixed external temperature of 2 °C. With H we mean the Healthy case, while EF means Evaporator fouling. In the simulation columns are reported also the percentage deviation with respect to the real case.

From the results, we can notice a reduction of the performances in both real and simulation for a single operating condition. The model behaves like the real HP, except the evaporator air outlet temperature. This is due to the fact that in the fan definition we set a fixed air mass flow rate the fan has to move. With fouling, in the real scenario, we have a reduction of the air mass flow rate due to the obstruction. Instead, in the model, the fouling factor does not block the air flow, but it behaves like a less efficient exchange material. Nevertheless, the main effects are the same, as can be seen in the table 2.

Condenser fouling

The dual problem of the evaporator fouling, is the condenser fouling. In our case, the condenser refers to the water, i.e. in Heating mode, it is the responsible of the thermal load. Fouling in the condenser can occur with debris accumulating in the water or water-glycol. If the water circuit is not regularly maintained with regular filter cleaning or other rarer faults, limestone or sediments can become stuck inside the condenser, causing an inefficient heat exchange.

In the laboratory, replicating this fault is much more difficult to be replicated than the evaporator. Fortunately, we can simulate this fault very easily by tweaking the fouling factor of the condenser plate heat exchanger. As expected, the condenser fouling has a negative impact on system behaviour, the main effects are: reduced thermal efficiency, increased pressure and compressor speed and decreased COP.

The simulation was carried out by setting a sinusoidal external temperature, ranging from -5 to + 15 °C. The thermal load is constant with a water inlet and outlet temperature, respectively of 30 °C and 35 °C. Constant is also the water mass flow rate at 0.5 kg/s and constant superheat setpoint at 10 K.

Description - a: suction temperature, b: condensation temperature, c: evaporation temperature, d: discharge temperature, e: COP, f: COP

It is useful to provide insights on how much energy could be saved in a clean and efficient plant. The profile simulates how many hours per year a certain external temperature is met with the same thermal load at the condenser. Here we consider the profile of Milan.

Milan profile - Annual Electrical Energy Consumption per Temperature

Considering an average energy cost of 0,25 €/kWh, the simulated evaporator fouling will result in an extra cost of 328 € per year.

Future developments and conclusions

To conclude, we have presented a useful approach to generate semi-realistic datasets and simulate faults inside the plant easily in a short time. This is very useful to develop and test anomaly detection algorithms. Indeed, this tool helped us choosing the right algorithm to further develop, since we can test various approaches in a very limited amount of time. Rather, in the laboratory the algorithm tests are more complicated and not ever possible because they are time and resources demanding.

This blog post is based on the paper “Dynamic Modelling and Simulation of Faults in an R290-based Air-to-Water Heat Pump System”, presented on 6 June at Clima 2025, held at the Politecnico di Milano.
The paper was authored by Daniele Scapin and Mirco Rampazzo from the Department of Information Engineering (DEI), University of Padua, and Riccardo Pengo, Chiara Corazzol, and Willy Muvegi from CAREL Industries S.p.A.

References:

S. Capanelli (2021). Benefits and reliability of air-to-water heat pumps in residential applications, using R-290 refrigerant and an alternative design solution to guarantee high safety with standard components.
Siegel, Jeffrey & Walker, Iain & Sherman, Max. (2002). Dirty air conditioners: Energy implications of coil fouling. Proceedings of the 2002 ACEEE Summer Study on Energy Efficiency in Buildings. 1. Bott, T. R. (1995). Fouling of Heat Exchangers. Elsevier.
Braun, J. E. (1998). "Reducing energy costs and peak electrical demand through optimal control of building thermal storage." HVAC&R Research, 4(1), 59-80.
Yan, K., Huang, S., & Wang, S. (2021). "A data-driven multi-level anomaly detection method for rooftop unit HVAC systems." Energy and Buildings, 253, 110975.
Tang, J., Zhang, F., Zhao, Y., Wen, T., & Zhang, X. (2021). "A hybrid fault detection and diagnosis strategy for air source heat pump heating system based on a physical model and deep learning." Applied Thermal Engineering, 197, 117965.
Minsung Kim, W. Vance Payne, Piotr A. Domanski (2006). Performance of a residential Heat Pump operating in the cooling mode with single faults imposed. NIST.
MathWorks. Simscape Product Documentation.
Cengel, Y. A., & Boles, M. A. (2015). Thermodynamics: An Engineering Approach. McGraw-Hill EducationDing.
IEA Heat Pump Centre. (2020). Heat Pumps: Technology and Applications.
ASHRAE. (2021). ASHRAE Handbook: Fundamentals.
Dossat, R. J., & Horan, T. J. (2002). Principles of Refrigeration (5th ed.). Pearson.
Stoecker, W. F., & Jones, J. W. (1982). Refrigeration and Air Conditioning. McGraw-Hill.
Granryd, E. (2011). Refrigerating Engineering. Royal Institute of Technology (KTH).
Recknagel, H., Sprenger, E., & Schramek, E.-R. (2020). Handbook of Heating, Ventilation, and Air Conditioning Technology. Springer.
CoolProp Developers. CoolProp Documentation.
Willmott, C. J., & Matsuura, K. (2005). "Advantages of the Mean Absolute Error (MAE) over the Root Mean Square Error (RMSE) in Assessing Average Model Performance." Climate Research, 30(1), 79-82.
Y. Alkurdi (2024). Anomaly Detection in Heat Pumps: Experimental Setup, Testing, and Data Analysis (Master Thesis).

Fault simulation in heat pumps with propane (part 1)

Monoblocks: modular solutions for commercial refrigeration

2025-10-09T07:00:19Z

Every day, millions of people walk into supermarkets, butchers', delicatessens, and grocers' in search of fresh, safe, and high-quality products. The increasing demand for food is accompanied by the search for variety regardless of seasonality and the place of origin of the products.

Consequently, being able to store, preserve and control ripening processes of produce is the key to meeting consumer demands and maximising store revenues according to demand in doing so.

Monoblock units for cold rooms

Two approaches are typically used for managing refrigeration in cold rooms:

Modular, in which one or more monoblock units are installed in each cold room
Centralised, in which one or more evaporators installed inside the cold room are combined with an external condensing unit or central refrigeration unit

The modular approach is ideal for small-volume cold rooms (up to about 50 m3 in size) and also simplifies installation and integration.

The monoblock solution is characterised by:

Ease of installation: it is quick and easy to set up, cutting start-up costs because there is no need for highly specialised technical personnel.
Compactness: the compact design and the availability of wall-mounted and ceiling-mounted models allow users to modulate their choice according to the available space.
Reliability: the units are factory-assembled. Mass production reduces the risk of refrigerant leakage and simplifies diagnostics in the event of faults. Furthermore, advanced electronic controls, such as IJF, can constantly monitor unit operation and promptly identify any faults.

The centralised approach is generally more common for larger refrigeration capacities. However, installing multiple independent units, possibly connected in a network, in the same cold room means that the monoblock units can also be employed in refrigerated warehouses and storage centres.

R290 and low environmental impact

Environmental sustainability is an increasingly important factor when choosing refrigeration units. With the entry into force of the new F-Gas regulation, which progressively restricts the use of fluorinated gases with high GWP (Global Warming Potential), there is a growing interest in natural refrigerants, such as propane (R290).

Propane is a natural gas with a very low GWP (equal to 3). It offers excellent thermodynamic performance and minimal environmental impact.

Some manufacturers, when designing high-efficiency units, choose to integrate the management of variable speed Vcc compressors and continuous modulation into the superheating control using an ExV electronic valve, extending the range of on/off units with the inclusion of premium models.

Therefore, the choice of intelligent control solutions is crucial in implementing optimised logic, capable of minimising consumption in all phases of unit operation. Control logics designed to ensure temperature stability, adapt unit operation according to door opening and minimise the number and time of defrost events are the key to reliable solutions and low energy consumption.

Minimising food waste

UNEP's 2024 Food Waste Index Report reveals that 1.05 billion tonnes of food were wasted globally in 2022, with the catering and retail sectors contributing 290 million and 131 million tonnes of waste, respectively. The report identifies inadequate storage conditions as one of the main causes of food waste, mostly due to sub-optimal or lacking product refrigeration.

The availability of simple solutions facilitates the adoption of systems that guarantee optimal food storage conditions.

Precise temperature control in cold rooms, sometimes combined with ambient condition maintenance in terms of humidity and gas concentration (e.g. CO₂ or ethylene), can maximise the product life cycle. This extends the period of availability for sale, increasing the likelihood that the goods will be purchased and the food will not go to waste.

The adoption of the monoblock solution for cold rooms guarantees high reliability, supporting service continuity that avoids interruptions in the cold chain.

Integrating supervisory systems for monitoring storage conditions is an additional support in identifying anomalies and taking timely action to resolve problems as a consequence.

Scalability at the service of sustainability

Simple installation and compact design facilitate the introduction of cold room refrigeration solutions throughout the cold chain, from local producers to point-of-sale distribution.
The use of modular solutions with propane monoblocks also facilitates the transition to environmentally friendly units, helping to meet growing demand sustainably.

Smart refrigeration: how Studio54 cut energy use and boosted food preservation

2025-10-02T07:00:18Z

In professional kitchens, cold storage is a silent but essential partner. Whether in hotels, restaurants or catering services, reliable refrigeration ensures that food is preserved safely, consistently and with minimum waste. Yet, behind those stainless-steel doors, refrigeration technology is undergoing a transformation. Italian manufacturer Studio54, based in San Giorgio in Bosco (Italy), has taken up the challenge of combining design, performance and sustainability in its latest line of professional freezer cabinets.

A new landscape for professional refrigeration

For many years, refrigeration manufacturers have focused on delivering robust, high-capacity units with low noise levels. However, the industry is facing fresh challenges. Regulations such as the F-Gas rules on refrigerants and the Ecodesign for Sustainable Products Regulation (ESPR) in Europe are pushing companies to rethink their technologies.

The emphasis is now on natural refrigerants and energy efficiency, with pressure to reduce environmental impact at every stage, from design and materials to performance during daily use. In this context, advanced technologies such as variable capacity compressors (VCC) are emerging as key solutions. Unlike traditional on/off compressors, which work at full capacity or not at all, VCC systems can modulate their speed to match actual cooling demand. In this scenario, the electronic thermostat plays a crucial role in achieving the maximum energy efficiency that the VCC compressor can provide. Thanks to its advanced algorithms, it can determine the optimal compressor speed for any situation. The result is greater efficiency, more stable temperatures and less energy waste.

The Studio54 approach

Studio54 has been a reference point in professional refrigeration since its foundation in 1994. Known for its focus on research, innovation and Italian design, the company set out to create a freezer cabinet that would stand out not just for its looks, but for its energy performance.

The challenge was twofold:

to deliver a premium unit that could meet the high expectations of the Ho.Re.Ca. market;
to reduce energy consumption while ensuring top-level food preservation.

Achieving both goals required a new approach to compressor management and cabinet design.

From on/off to variable speed compressors

To understand the impact of VCC technology, Studio54 carried out comparative tests between traditional fixed-speed compressors and the new modulating system. The tests were performed according to ISO 22041/EN16825:2016, simulating real kitchen conditions.

The results were striking.

Fixed-speed compressors operated with distinct on/off cycles, which naturally led to temperature fluctuations. During events such as door openings or defrosting, the sensors inside the cabinet recorded peaks and troughs, reflecting the reactive nature of the system. While this approach has long been standard, it can result in increased mechanical wear, higher energy consumption, and variable food preservation performance. VCC systems, on the other hand, bring a new level of precision. By modulating their speed continuously, they kept temperatures much closer to the set point. Gradual adjustment of compressor frequency minimised abrupt cycling and produced a smoother cooling curve. Even under demanding conditions – such as frequent door openings – the system responded swiftly, stabilising temperatures faster and ensuring uniform cooling throughout the cabinet.

Energy savings in practice

The shift to variable-capacity technology not only involves stability. It also brought measurable energy benefits. Studio54’s tests showed that daily energy consumption dropped from 5.8 kWh/24h to 3.3 kWh/24h, a 43% reduction.

Part of this saving – about 1.5 kWh per day – was directly attributable to the VCC system, while other design improvements contributed to the rest. Importantly, the cabinet’s official energy class improved from D to B, a leap of two ratings that reflects not just lower running costs, but also a reduced environmental footprint.

Real-world impact

For food service operators, the implications are clear. Lower energy use translates into reduced operating costs. More stable cabinet temperatures mean better food quality and safety, with fewer risks linked to fluctuations. And the environmental benefits – reduced electricity demand and better refrigerant management – align with the growing demand for sustainable solutions across the hospitality sector.

As Studio54’s CEO, Marco Bruseghin, put it during the testing phase, the aim was not simply to comply with regulations, but to set a benchmark for sustainable refrigeration in the industry.

Looking ahead

The case of Studio54 illustrates how traditional industries are rethinking their products in response to environmental and market pressures. The combination of innovation, design and testing has allowed the company to deliver equipment that is not only more efficient, but also aligned with the values of today’s hospitality sector: sustainability, cost control, and a premium customer experience.

The transition from on/off compressors to variable-capacity systems may seem like a technical detail, but the impact of the electronic thermostat is key to achieving the highest energy efficiency from VCC compressors. In a market where every kilowatt-hour saved matters – both financially and environmentally – such advances show how refrigeration can contribute to a smarter, greener future.

Read the success story

B2B and emerging social media: is the time right to try Threads?

2025-09-25T07:15:13Z

In the world of B2B communications, and especially in a technical sector such as HVAC/R, the choice of which channels to use is never a trivial one. Each platform has its own identity, its own language, its own expectations. And while LinkedIn is undoubtedly still the point of reference, lately there has been a lot of talk about Threads, the social network launched by Meta as the possible heir to Twitter (now X), which seems to be on an increasingly downward spiral.

However, the real question is: is Threads really ready for industrial B2B?

Let’s start with what we know. LinkedIn, even in 2025, is still the primary channel for B2B communications. Indeed, 85% of B2B marketers consider it the platform with the best organic ROI, and for good reason: precise targeting, professional context, valuable content, and the ability to speak directly to industry experts, buyers, and decision-makers. Looking at HVAC/R specifically, LinkedIn is the natural place to publish and/or promote white papers, case studies, webinars, and even announce corporate and product updates.

Threads was established in July 2023 with the ambition of becoming the alternative to X, at a time when the platform acquired by Musk was experiencing quite a bit of uncertainty. It’s initial growth was rapid, and Threads is now one of the most downloaded apps every month: as of August this year, it had more than 350 million active monthly users.

This number means the platform is inching closer to X’s 600 million monthly users, with the gap rapidly narrowing, especially considering the decline of X (which has lost 15% of its traffic in Europe since Elon Musk took over).

Threads’ opening to advertising, the introduction of analytics tools, and direct messaging seemed to signal its expansion into the business sphere.

Two years after its launch, however, the business landscape - at least in the HVAC/R sector - looks quite different.

Regarding tech and digital B2B, some companies (e.g. Hootsuite, HubSpot, and Mailchimp) have already begun experimenting with Threads, adopting a more informal, conversational, and at times even self-deprecating tone.
In the industrial and manufacturing segments, however (including HVAC/R), Threads is still used sporadically and often without any specific structure.

Some large industrial groups have opened a Threads profile and have started publishing content, yet:

in some cases, they stopped after just a few months
in other cases, even with tens of thousands of followers, interactions are minimal: a handful of likes, almost no comments, and very low engagement compared to the potential audience.

These attempts are therefore “observational”, without a true editorial strategy or clear objectives.

So is it too early for Threads? It seems that for now, Threads is not yet ready to take the place of X for technical-industrial B2B. Some companies have actually “left” X, but haven’t (yet) switched to Threads as a valid alternative. To date, only 19% of B2B companies have started posting on Threads, demonstrating that in reality only a small portion of the sector is starting to explore the platform.
And this is not (only) the platform’s fault: Threads is probably still too young to significantly attract the attention of companies with more traditional communication models.

Moreover, interaction on Threads is based on rapid-fire, almost “emotional” language, which pairs well with lifestyle or consumer content. Translating this language into the HVAC/R context requires a creative and strategic effort, which, at the moment, few businesses seem willing to undertake.

There is however another way to look at it. As the platform is not yet crowded, and the big players in the industry are only using it marginally, Threads could become an ideal space for experimentation.

For example, consider technical questions to engage the community, regulatory news explained in a more accessible way, short videos, or behind-the-scenes images of systems or installations.

Even with modest initial engagement on Threads, this content could then be reused on other channels and become a starting point for connecting with a different audience, perhaps even younger or more curious people.

In actual fact, the target that uses this social network is not that much “younger” than that of LinkedIn: the largest age group (29%) is the 25 to 34 year olds. Threads is therefore mainly used by Millennials and older Gen Zs who are in the early or intermediate stages of their career.

In conclusion then, LinkedIn is still the key platform for B2B HVAC/R. Threads, on the other hand, is still in the exploratory phase and doesn’t yet seem ready to welcome those who have abandoned X, but for this very reason, now might be the perfect time to start testing it, without having too-high expectations, rather with the desire to innovate and stay ahead of the times.

Indeed, while it’s true that Threads isn’t yet the ideal channel for technical B2B, it could become one. And whoever gets there first often finds themselves with a competitive advantage that is hard to make up.

Sources:

Ninja Marketing - https://www.ninja.it/crescita-di-threads-2025/
Business of Apps – Threads Statistics 2025 - https://www.businessofapps.com/data/threads-statistics/
Reuters – Meta opens Threads to advertisers globally (April 2025) - https://www.reuters.com/business/media-telecom/meta-opens-threads-advertisers-globally-2025-04-23/
VisitorQueue – Threads for B2B - https://www.blog.visitorqueue.com/should-your-b2b-company-use-threads-a-how-to-guide/
Marketing Eye – Threads nel marketing B2B - https://www.marketingeye.com/blog/social-media/how-threads-could-transform-your-b2b-marketing-landscape.html
Mobile Marketing Magazine – https://mobilemarketingmagazine.com/threads-gains-momentum-among-brands-research-reveals/
Startup Guru Lab – https://startupgurulab.com/threads-statistics

EU cybersecurity actions in the context of the HVAC/R sector

2025-09-18T07:00:20Z

Have you ever stopped to consider what would happen if a cyberattack targeted an HVAC/R system? These technologies are often the quiet workhorses behind our comfort and safety, responsible for preserving products and maintaining healthy environments. As a result, vulnerabilities can lead to consequences that go far beyond just compromised data. A successful cyberattack can disrupt essential services and compromise the safety and reliability of HVAC/R systems, potentially affecting building operations, occupant comfort, and even critical infrastructure. That’s why cybersecurity across all sectors, including ours, is becoming a strategic priority for the European Commission (EC).

The focus on cybersecurity in the European Union (EU) began at the beginning of the 21^st century, as the internet became an important part of the economy and society. In 2000, the EC published a key communication outlining the need to secure digital infrastructure and fight computer-related crime.¹ However, it wasn’t until 2007 that cybersecurity was widely recognised as a critical issue across the EU. This happened after a wave of coordinated cyberattacks on Estonia disrupted government and financial services², marking a turning point and sparking more comprehensive action at an EU level.

Since then, the EC has developed a series of initiatives and regulations that make one thing clear: cybersecurity is a shared responsibility. This includes those of us working with HVAC/R technologies, which are becoming more connected, intelligent, and essential to critical infrastructure. Let’s take a closer look at the key EU actions shaping this evolving landscape.

Laying the foundations: ENISA and the definition of the strategy

In 2004, the EC created ENISA³, its first agency focused on cybersecurity. The function of ENISA is to achieve a high common level of cybersecurity across Europe, contributing to EU cyber policy, enhancing the trustworthiness of ICT products, services and processes with cybersecurity certification schemes, cooperating with Member States and EU bodies, and helping Europe prepare for the cyber challenges of the future. ENISA regularly publishes guidelines for securing Internet of Things (IoT) systems⁴, which directly apply to HVAC/R equipment that uses smart sensors, remote controls, or cloud connectivity.

The first EU Cybersecurity Strategy⁵ was adopted in 2013. It emphasised protecting networks and information systems across the EU, supporting cybercrime enforcement, and developing industrial capabilities. The strategy was updated in 2020 to reflect the increasing complexity of cyber threats. This updated strategy, called the “EU Cybersecurity Strategy for the Digital Decade”, focused on securing digital infrastructure, building EU-wide resilience and promoting international cooperation. The EU Cybersecurity Strategy clearly applies to the HVAC/R sector through its focus on connected devices, critical infrastructure, and supply chain security.

How has the EU regulated cybersecurity in the last years?

Over the past few years, the EC has been particularly active in introducing cybersecurity regulations, many of which directly affect connected HVAC/R operators and products.

First, as part of the EU Cybersecurity Strategy, the Cybersecurity Act⁶ was adopted in 2019. It marked one of the first major steps toward a coordinated European response to cyber threats. In particular, this Act significantly strengthened the role of ENISA, granting it a permanent mandate and expanding its responsibilities in operational cooperation and crisis management across Member States. It also provided ENISA with increased financial and human resources, enabling the agency to better support cybersecurity efforts throughout the EU. Interestingly, ENISA originally stood for “European Network and Information Security Agency”, a name that was replaced in 2019 by “European Union Agency for Cybersecurity” to reflect the agency’s broader role.

In 2016, the Directive on Security of Network and Information Systems (NIS Directive) was published, which required essential service operators to take appropriate security measures. Essential service operations include energy, transport, health, and digital infrastructure. This Directive was updated in 2022, with the publication of NIS2⁷, which expands the scope and requirements of the original NIS Directive. Specifically, the new rule applies also to providers of public electronic communications, more digital services, waste and wastewater management, critical product manufacturing, postal and courier services, and public administration at both central and regional levels, as well as the space sector. Requirements include policies for supply chain security, vulnerability management, and cybersecurity education and awareness. In terms of timing, NIS2 mandated each Member State to adopt a national cybersecurity strategy by October 2024.

In NIS1 HVAC/R was not explicitly covered, unless it was part of a critical service (e.g. a cooling system in a hospital or data centre). In those cases, the operator (not necessarily the HVAC/R supplier) was responsible. However, HVAC/R manufacturers or service providers can fall under NIS2 if their products are used in critical infrastructure, provide remote monitoring, IoT connectivity, or software related to HVAC/R, and are medium or large-sized companies (generally 50+ employees or €10M+ turnover) in a relevant supply chain.

The Cyber Resilience Act (CRA)⁸ entered into force on 10 December 2024, being the first European regulation to mandate cybersecurity requirements for all products with digital elements placed on the EU market. It establishes common standards for products with digital elements, including hardware and software. Such products must meet specific cybersecurity requirements throughout their lifecycle, including automatic security updates and incident reporting. The Act also introduces a duty of care for manufacturers, ensuring that products are secure by design and by default. CRA applies from December 11, 2027 (except for conformity assessment bodies, which must comply by 11 June 2026; and reporting obligations on manufacturers, which become mandatory from 11 September 2026).

According to the CRA, HVAC/R companies producing smart equipment will need to integrate cybersecurity into product design, development, and lifecycle management. For instance, they will need to ensure that the firmware is secure, regularly updated, and protected against known cyber threats. They will also have to report vulnerabilities, offer proper user guidance, and demonstrate compliance to place the product on the EU market.

The Radio Equipment Directive Delegated Act (RED DA)⁹, adopted in 2021, is another important part of the EU’s cybersecurity framework. It builds upon the existing Radio Equipment Directive (RED), adding safety, health, and electromagnetic compatibility requirements for devices that use radio frequencies and can connect to the internet. This Act is relevant to wireless and connected products, potentially including some HVAC/R devices that use wireless communication (i.e. WiFi, Bluetooth, or cellular). The RED Delegated Act will apply starting August 2025.

The RED DA also has a direct impact on the HVAC/R sector, particularly for products with wireless communication capabilities such as WiFi-enabled smart thermostats or Bluetooth-connected HVAC control panels, refrigeration units that send data via cellular networks to a cloud platform, or wireless temperature/humidity sensors.

Summary and conclusion

To sum up, the EU Cybersecurity Strategy (2013) outlines the broad vision for building a resilient digital Europe, while the Cybersecurity Act (2019) puts that vision into practice by strengthening ENISA and creating a certification framework to ensure product security. Alongside these, there are regulations such as the Radio Equipment Directive Delegated Act (2021) that addresses cybersecurity in wireless and radio equipment, the NIS Directive, now updated as NIS2 (2022), which mandates cybersecurity measures for critical infrastructure operators, and the Cyber Resilience Act (2024) that sets security requirements for digital products. All these work together to protect connected systems, including those in the HVAC/R sector.

Complying with cybersecurity policies is not just another challenge for our sector, but a critical priority. In an increasingly connected world, securing our systems is no longer optional. It is a shared responsibility to ensure their safety and trustworthiness.

References:

¹. https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=COM:2000:0890:FIN:EN:PDF
². https://www.wired.com/2008/04/estonia-natos-b/
³. https://www.enisa.europa.eu/
⁴. https://www.enisa.europa.eu/publications/baseline-security-recommendations-for-iot
⁵. https://digital-strategy.ec.europa.eu/en/policies/cybersecurity-strategy
⁶. https://digital-strategy.ec.europa.eu/en/policies/cybersecurity-act
⁷. https://digital-strategy.ec.europa.eu/en/policies/nis2-directive
⁸. https://digital-strategy.ec.europa.eu/en/policies/cyber-resilience-act
⁹. https://www.enisa.europa.eu/

Cybersecurity and data centres: IT vs OT

Cyber Security during the COVID-19 pandemic: from social distancing to social engineering

Fault simulation in heat pumps with propane (part 1)

2025-10-16T09:03:59Z

Heat pumps are very important units in the current HVAC systems. They work through the process of transportation of heat energy from a source to another destination thus offering both heating and cooling options. With increasing energy efficiency standards all around the world and the increasing need for energy efficient heating and cooling systems, heat pumps have become an essential part of modern building systems. The good functioning of heat pumps is crucial to the delivery of thermal comfort.

Anomalies in heat pump systems will result in variations in performance. These anomalies may appear as deviations from the standard working conditions, including variations in temperature, pressure and energy consumption. Some of the causes include heat exchanger fouling, refrigerant loss, sensor faults, and incorrect control settings. Identifying these anomalies at an early stage is crucial, as their persistence can lead to increased energy consumption, thermal discomfort to the user, reduced component lifespan, and even system failure.

To analyse the effects of the various anomalies, we can set up some laboratory tests. In this way, we can investigate in detail the consequences of fouling in the evaporator and condenser, in addition to undercharge and overcharge tests. Nevertheless, these tests require a lot of time to reach the desired set point and conditions to achieve fair comparisons between healthy and anomalous conditions. A way to solve this problem, is to simulate the heat pump behaviour of healthy and faulty situations in a simulation software that provides a library of prebuilt components that can be connected graphically to represent real-world systems.

We replicated a model of a domestic air-to-water Heat Pump with a nominal heating capacity of 7 kW, with R290 propane refrigerant (Table 1). In the next chapters we will present its model validation, as well as the evaporator fouling analysis with the model and the real machine.

Heat pump functioning

A Heat Pump transfers heat from a low-temperature source, which might be the ambient air, ground, or water, to a higher-temperature sink, usually an air conditioning system using a refrigerant.

The efficiency of a heat pump is expressed as the Coefficient of Performance (COP), defined as the ratio of useful heating or cooling power, divided by the absorbed electrical power.

The operation of a heat pump is based on the vapor-compression refrigeration cycle, which involves four main stages:

Compression: The refrigerant enters the compressor as a low-pressure gas. The compressor increases its pressure and temperature, converting it to a high-pressure, high-temperature gas.
Condensation: The high-pressure gas flows into the condenser, where it releases heat to the sink and condenses into a high-pressure liquid.
Expansion: The high-pressure liquid passes through the expansion valve, where its pressure drops. This process causes the refrigerant to cool and partially vaporize.
Evaporation: The low-pressure refrigerant enters the evaporator, where it absorbs heat from the source. This heat causes the refrigerant to evaporate into a gas, completing the cycle.

Refrigerant type	R290
Charge weight	3.1 kg
COP A2/W35 (EN14511)	4.54
COP A7/W35 (EN14511)	5.47
Electrical Power A7/W35 (EN14511)	3.3 kW
Absorbed current A7/W35 (EN14511)	16 A
Nominal Power A7/W35 (EN14511)	7 kW

Table 1. Heat Pump nominal data

Simulation model

Every simulated component has been calibrated to behave like its respective real. Accordingly, this means that their geometrical and technical parameters are not exactly the same.

Some characteristics of the component are not provided by the manufacturer, so we kept the default values. Other parameters, such as geometries, were measured or estimated by us, which introduces a degree of human uncertainty that must be considered.

As said before, the model is based on a real machine. Therefore, we decided to report the obtained validation scores by calculating the “differences” between them. We run the simulations by setting the same conditions encountered in the real tests (the real tests are all stable and stationary conditions collected in over 3 months, for a total of 113 different points). These conditions are: external temperature (from 0 °C to 15 °C), superheat (from 8 K to 12 K), water inlet and outlet temperature (from 25 °C to 40 °C), fan speed and water mass flow rate (from 15 l/min to 30 l/min). As metrics we adopted the Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), std error and maximum error. The model performs well for most variables, especially for pressures and condensation temperatures with RMSE values of 0.3 barg and 0.1 barg. Suction and discharge temperature show relatively higher RMSE values of 3.0 K.

In this first part, we explored the crucial role of heat pumps in modern HVAC systems, highlighted the challenges in detecting faults early, and validated a simulation model. This model proved to be a reliable and flexible tool, capable of realistically replicating the behaviour of a real heat pump and enabling detailed analysis of operating conditions and system anomalies.

In the second part, which will be published in the coming weeks, we will dive into the use of the model for synthetic data generation under faulty scenarios. We will focus in particular on evaporator fouling, comparing simulation results with real experimental data. The discussion will then extend to condenser fouling. Finally, we will outline potential future developments.

References:

S. Capanelli (2021). Benefits and reliability of air-to-water heat pumps in residential applications, using R-290 refrigerant and an alternative design solution to guarantee high safety with standard components.
Siegel, Jeffrey & Walker, Iain & Sherman, Max. (2002). Dirty air conditioners: Energy implications of coil fouling. Proceedings of the 2002 ACEEE Summer Study on Energy Efficiency in Buildings. 1. Bott, T. R. (1995). Fouling of Heat Exchangers. Elsevier.
Braun, J. E. (1998). "Reducing energy costs and peak electrical demand through optimal control of building thermal storage." HVAC&R Research, 4(1), 59-80.
Yan, K., Huang, S., & Wang, S. (2021). "A data-driven multi-level anomaly detection method for rooftop unit HVAC systems." Energy and Buildings, 253, 110975.
Tang, J., Zhang, F., Zhao, Y., Wen, T., & Zhang, X. (2021). "A hybrid fault detection and diagnosis strategy for air source heat pump heating system based on a physical model and deep learning." Applied Thermal Engineering, 197, 117965.
Minsung Kim, W. Vance Payne, Piotr A. Domanski (2006). Performance of a residential Heat Pump operating in the cooling mode with single faults imposed. NIST.
MathWorks. Simscape Product Documentation.
Cengel, Y. A., & Boles, M. A. (2015). Thermodynamics: An Engineering Approach. McGraw-Hill EducationDing.
IEA Heat Pump Centre. (2020). Heat Pumps: Technology and Applications.
ASHRAE. (2021). ASHRAE Handbook: Fundamentals.
Dossat, R. J., & Horan, T. J. (2002). Principles of Refrigeration (5th ed.). Pearson.
Stoecker, W. F., & Jones, J. W. (1982). Refrigeration and Air Conditioning. McGraw-Hill.
Granryd, E. (2011). Refrigerating Engineering. Royal Institute of Technology (KTH).
Recknagel, H., Sprenger, E., & Schramek, E.-R. (2020). Handbook of Heating, Ventilation, and Air Conditioning Technology. Springer.
CoolProp Developers. CoolProp Documentation.
Willmott, C. J., & Matsuura, K. (2005). "Advantages of the Mean Absolute Error (MAE) over the Root Mean Square Error (RMSE) in Assessing Average Model Performance." Climate Research, 30(1), 79-82.
Y. Alkurdi (2024). Anomaly Detection in Heat Pumps: Experimental Setup, Testing, and Data Analysis (Master Thesis).

Fault simulation in heat pumps with propane (part 2)

Reinventing the supply chain with a “Globally Local” approach

2025-09-04T07:00:19Z

In a world increasingly shaped by geopolitical shifts, trade uncertainties, and environmental challenges, companies operating globally must rethink how they structure their supply chains and manufacturing models. One strategic response that is proving particularly effective is the “local for local” approach. This model prioritises localising both production and procurement as close as possible to the markets being served, allowing for increased autonomy, resilience, and customer responsiveness.

Under this model, manufacturing sites are not centrally dependent but are instead designed to be multi-product facilities capable of supporting their regional demand independently. This setup makes them less exposed to local disruptions, whether logistical, political, or environmental. In parallel, the procurement of components is also localised wherever possible. This strategy leads to shorter lead times, reduced inventories, and greater supply continuity, which is especially important in volatile global contexts.

A fundamental element of this approach is the development of “second sources”, alternative suppliers or manufacturing capabilities that can act as backups in the event of disruption. This diversification strengthens operational resilience and enhances the ability to respond quickly to unexpected shifts in supply or demand.

The natural evolution of the local-for-local model is the creation of fully localised supply chains, tailored to the specific market in which a product is used. This helps meet local regulatory or “made in” requirements and minimises the financial and operational impact of import duties or restrictive trade policies. As protectionism rises in some regions, local manufacturing becomes a strategic necessity rather than just an efficiency-driven decision.

Balancing localised production with consistent global standards is achieved through the adoption of “mirrored technologies”. This means the same product can be manufactured in different sites using identical processes and equipment, ensuring technological consistency, operational redundancy, and high-quality standards across the board. This technological mirroring supports flexible production reallocation across regions when needed and ensures that the end customer receives the same level of quality regardless of where the product was made.

To support this operational agility, companies are heavily investing in digitalisation. Real-time visibility across global production networks enables better decision-making, early detection of bottlenecks, and the ability to proactively shift workloads across facilities. Monitoring hundreds of production lines across multiple locations allows for dynamic production planning and continuous improvement in customer service.

Investments in emerging markets such as Mexico, India, or Vietnam are not driven by a desire to relocate production for cost reasons but rather to serve local markets more efficiently and comply with regional constraints. These efforts often take the form of small facilities or strategic collaborations with local partners, further reinforcing the commitment to localisation without sacrificing flexibility.

Innovation also plays a key role. For fast-moving technologies or products with short life cycles, open innovation and strategic partnerships are essential to accelerate time-to-market. At the same time, for core and differentiating technologies, companies must invest directly in internal R&D to protect intellectual property and maintain competitive advantage.

Lastly, open and fair trade policies remain a critical enabler of global efficiency. While some regulation is necessary to avoid unfair competition, excessively protectionist measures can hinder access to the most efficient or innovative suppliers. A transparent, rules-based market supports industrial growth and customer value creation.

Global R&D capabilities, combined with centralised decision-making and advanced digital controls, ensure that companies can quickly adapt to local regulatory changes while maintaining brand consistency and quality across all markets. This globally local model is becoming not just a trend, but a strategic imperative for companies seeking long-term resilience and sustainable growth.

Optimising paint booth performance through integrated climate and fan control

2025-08-28T07:00:34Z

To obtain the maximum advantage from the use of high-efficiency components, the paint booth must be equipped with an automatic control system for integrated management of all the variables.

The use of advanced logic to optimise the operation of high-efficiency components, such as modulating fans, direct expansion systems, heat pumps, adiabatic humidifiers, evaporative coolers, heat exchangers and motor-driven dampers, brings significant reductions in energy consumption, without impacting the quality of the painting process.

The electronic control is the heart of the ventilation system serving the paint booth. It is what makes the difference between an effective and efficient system, and a system that cannot meet the process requirements. To ensure optimal control over time, the electronic control needs to be connected to appropriate sensors that are used to activate and manage the various air handling unit (AHU) devices. Additional sensors and control devices are then needed to detect and manage alarms and limit conditions.

What are the most important components of an air handling unit serving painting processes?

Fan control

Fan control is important for maintaining the rated operating conditions of the air stream. Given how critical this aspect is, paint booths do not use simple ON/OFF fans, but rather modulating fans. The controll modulates fan speed during operation, and manages all the safety checks to be carried out when switching ON and OFF and in the event of alarms.

The ON/OFF sequence, with corresponding timing, depends on the interaction with the other AHU devices. One typical example involves switching the fan OFF together with the electric coil or the gas burner: in this situation, the fan should be kept ON even after an OFF command, to ensure the residual heat is carried away, avoiding overheating the components and damaging the combustion chamber.

Variable fan speed is also used to compensate for changes in pressure drop both inside and outside of the AHU and thus keep the flow-rate constant. Furthermore, in some paint booths, multiple flow-rate set points may be needed for different processes or phases. To control the fan speed, simply measure the air speed in the duct or the differential pressure. For stable control, a PID (proportional integral derivative) algorithm is strongly recommended.

Example of inverse proportional control for pressure-based fan control

One very common solution for offsetting pressure drops involves the use of radial fans with pressure measurement directly at the inlet nozzle: as the pressure drop at the latter is calibrated, the differential pressure measurement allows the flow-rate to be monitored, therefore adjusting fan speed so as to keep this constant. Blocking of the filters, at the same speed, causes a reduction in flow-rate and therefore in the pressure drop at the inlet nozzle, and consequently the fan speed increases.

Pressure measurement at the fan’s calibrated inlet nozzle

Large AHUs often use multiple supply and exhaust fans. For example, two fans in parallel are a useful solution for allowing lower and wider AHUs where there are space constraints. In this case, it is simply a matter of duplicating the control outputs, keeping the same control probe but managing any flow or motor thermal overload alarms individually; an auxiliary function can be to provide an activation delay between the two devices, to both motors starting at the same time. The evolution of this concept has led to the use of multiple radial fans (two, four and more) arranged side-by-side to form what is referred to as a “fan wall”, with the aim of increasing redundancy and, often, reducing the size of the AHU. The control of two fans or a fan wall occurs in a similar way; however, when there are multiple devices, serial communication is recommended, so as to reduce the number of outputs needed and be able to monitor the status of each individual device independently.

Temperature and humidity control

Temperature and humidity control is necessary to maintain optimal air conditions inside the paint booth and guarantee the highest-quality painting process. This is done by modulating the opening of the control valves on heat exchangers, burners, humidifiers and other components, based on the readings of the sensors installed in the AHU supply duct.

Control on the supply air stream is the ideal solution, as the high number of air changes means that the supply temperature coincides with the temperature inside the booth. In this way, the sensors can be positioned in the clean air stream before being delivered into the paint booth, avoiding the need for expensive ATEX sensors inside the booth itself or in the exhaust air stream, where they would be subject to high levels of dirt and maintenance.

Temperature-humidity control depends on the outside air conditions, which may vary considerably depending on the time of year and the climate in the place where the system is installed. The most common function of temperature humidity control is heating, which is important both in the painting and curing phases, but also in intermediate phases such as bodywork preparation and drying. In many parts of the world, and for good control of process quality in general, air cooling is also needed. Furthermore, relative humidity control is fundamental and, depending on the technology used, also impacts the temperature, making control complex and therefore even more important to keep all the variables under control. Below are a couple of typical examples of integrated temperature and humidity control for adiabatic humidification and evaporative cooling.

In summary, the adoption of intelligent, integrated control systems is fundamental for ensuring optimal performance and energy efficiency in paint booth ventilation and air treatment. From precise fan modulation to stable temperature and humidity regulation, each component must be carefully coordinated to maintain the desired process conditions and reduce energy consumption.

In the next blog post, I will explore more advanced aspects of integrated control, focusing on adiabatic humidification, evaporative cooling, and heat recovery systems. These technologies play a key role in managing environmental conditions in a sustainable and cost-effective manner, don’t miss the upcoming article, where we’ll dive deeper into their control logic and practical applications.

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Skill matrix and physical training: what do they have in common?

2025-08-07T07:00:33Z

We live in a world where businesses need to be increasingly competitive and adaptable. To stay in the market, companies need to find the methods and means to develop their employees’ skills; as a result, their people too need to be open to continuous learning.

This aspect has become strategic in recent years, in the same way that physical training is for an athlete.

And, just like in any sport, companies also need a clear plan, a consistent routine, and the will to improve every day.

But what is a skill matrix and what is it used for?

A skill matrix is a visual tool that represents the who and the what—people and skills—within a team. A skill matrix can be used to:

map the current skills of individuals
identify areas for improvement
plan harmonious, continuous, and measurable development

I chose to describe this process using a sports metaphor, as the parallel is quite evocative:

skills are like exercises
training is learning
projects are the competition arena

Anyone who is used to working out seriously knows that just “randomly training” is not enough to truly improve. You need a structured program, clear goals, consistency, and measurement. The same applies to professional growth in a company.

Last week, while training, I reflected on how much similarity there actually is between a company’s skill matrix and a workout plan.

I identified six common elements:

1. Clear goals
Training always starts with a goal: building muscle mass, winning a competition, qualifying for the Olympics. Similarly, a skill matrix starts from a need: making a person autonomous, improving skills, or balancing competencies within the team. In both cases, growth doesn’t happen by chance. A clear direction is needed.

2. Check-up
Before designing a training plan, the coach evaluates the athlete’s physical condition, identifying the AS-IS state.
In a company, likewise, the HR department or manager assesses the competence level of team members. Without a measured starting point, it’s impossible to build a realistic development plan or track progress.

3. Personalised plan
Spoiler alert for some of you: no good coach gives all athletes the same training. The skill matrix must also be personalised based on the role, goals, and individual. There should be a balance between requirements of the role and personal ambitions.

4. Smart overload
In sports, effort increases progressively. Depending on the goal, the number of exercises, reps, or weights is adjusted.
At work, increasing challenges are assigned: shadowing, more complex projects, cross-functional roles. The skill matrix helps plan these “growth loads”, avoiding stagnation or unsustainable overloads.

5. The mirror and the trainer
An athlete sees their results and receives constant feedback from their coach. In companies too, a skill matrix is only useful if kept updated and integrated with real moments of discussion: periodic evaluations and one-to-ones.

6. Growth as a process
The training plan changes, it needs to adapt to progress, to be updated. A skill matrix, when used well, is a dynamic tool—not a file to be archived. It requires commitment, continuity, and above all, time.

All this to say that adopting a skill matrix in a company is not just an exercise—it’s a true training journey for skills. Like in sports, those who truly grow are those who are willing to measure themselves, to train, and to adapt over time.

Whether in sport or in business, the logic is the same: train to get stronger.

Efficiency and precision for an artisan product of excellence

2025-07-31T07:00:32Z

What do you know about cheese aging and ripening? How many factors help cheese have a delicious taste and nuances in flavour? Should the climate be warm or cold, ventilated or not? All these questions arise when dealing with cheesemaking. In the past, cheese aging was managed with natural storage inside caves, and there was considerable waste due to incorrect temperature, too high humidity or a lack of ventilation. Now, cheesemaking has become significantly easier, as cheese can be aged in optimum conditions.

Today cheesemakers face the problem of how to age their cheese by seeking the best way to combine traditional methods with innovative technologies.

For more than 50 years, Guglielmi Stagionatura has stood out for the quality of the service it offers numerous leading Italian cheesemakers, in particular for hard cheeses.

It now has a new solution available, thanks to the design and development work carried out by Merenti Refrigerazione, a local refrigeration company, and perfectly implemented in the Guglielmi Stagionatura facilities.

Guglielmi’s production site is located in the mountains in Valdastico, which helps prevent the cheese from being exposed to high temperatures and a lack of ventilation.

Yet the location is not the only important aspect for aging cheese: for higher quality and a perfect climate, something else is needed, which on one hand helps provide the best environmental conditions, and on the other reduces energy consumption.

The contractor thus decided to install a programmable controller and use a custom software application.

What can a custom application bring to cheese aging? Certainly temperature and humidity management during cheese storage, with the maximum flexibility.

The solution adopted provided the optional combination of multiple factors: the system uses advanced features such as free cooling, in which a damper is activated to let in outside air whenever the weather conditions allow, thus reducing energy consumption. The electronic expansion valves ensure accurate cooling control, while the external compressor rack optimises floating condensation pressure and heat recovery, bringing an overall reduction in energy consumption of around 30%.

To ensure the highest efficiency, the system was equipped with a supervisory system, capable of monitoring up to 50 devices. Connected via RS485 serial lines, the system centralises the data from the 16 active devices in the system, and sends notifications via email or Telegram in the event of alarms. This solution not only makes maintenance much simpler and more timely, but is also used to log the temperature and humidity data.

Furthermore, Guglielmi offers its customers the possibility to access a dedicated web site, where they can monitor the status of their wheels of cheese in real time while they are aging.

In 2023, Guglielmi opened a new processing plant for the production of artisan cheese. Here they make high-quality cheese, including blue cheese and other specialities. The storage rooms are managed by cold room controllers, designed to maximise flexibility and adapt to different processing needs. Each room is equipped with a humidity and temperature control module, as well as electronic valves for precise management of the refrigeration system. The new plant is also integrated connected to the supervisory system, ensuring continuous monitoring and perfect synchronisation with the existing operations.

Through this installation designed by Merenti Refrigerazione, Guglielmi was able to optimise the ripening process, ensuring stable environmental conditions, lower energy consumption, and higher quality of the end product.

The contents of this blog post can be examined more in depth by reading the success story
"Guglielmi Stagionatura: efficiency and precision for an artisan product of excellence"

Read the success story

Impact of air conditioning on relative humidity

2025-07-24T07:00:31Z

In buildings, especially those intended for commercial use, to achieve the recommended indoor air quality levels, the inside air needs to be diluted with air-conditioned and filtered air from the outside, as it contains pollutants and bioeffluents.

Take, for example, a hospital in winter; for the sake of simplicity, only fresh outside air is used - air that is very cold and humid (point A, temperature = -5°C, relative humidity = 80%). This is then heated by a coil in one of the hospital’s air handling units, undergoing a transformation whereby its temperature increases and its specific humidity (absolute moisture content in a given quantity of air) remains constant. The new temperature-humidity conditions of the air flow are now represented by point B, i.e. temperature = 22°C and relative humidity = 12%.

As a consequence of heating the air, the relative humidity - which expresses the relative moisture content in reference to the maximum that the air can hold at a given temperature before the moisture condenses - drops dramatically. The relative humidity has in fact fallen from the initial 80% of the outside air to about 12% in indoor air conditions, however without removing any moisture!

This is because the air, as it is heated, has increased the amount of water droplets in suspension (humidity) it can now "support".

Heating fresh outside air plotted on the Carrier psychrometric chart

The air flow will thus be delivered into the building in the conditions described by point B and, when mixing with the air already present inside the rooms, will bring about a gradual lowering of the indoor relative humidity.

From this example it is clear that the need for air change to ensure adequate IAQ has a direct relationship with the need to control humidity in the same environment. Even with low air change rates, the indoor environment will tend to become dry, while if adopting a ventilation criterion based on IAQ requirements or, as explained in the previous chapters, in order to minimises the risk of spreading infections, the air will become even drier, therefore representing a risk not only for the comfort of occupants but also for their health.

Given the importance of maintaining an adequate relative humidity level, a humidification system is needed to bring relative humidity back into the correct range. The humidification process can be implemented using an adiabatic system (line 1), by spraying very fine droplets of water into the air, or using an isothermal system (line 2), by boiling water to produce steam, which is absorbed by the air.

Heating and humidification of fresh outside air plotted on the Carrier psychrometric chart

Regardless of the humidification technology used, the system will work mainly during the winter, when the heating system lowers the relative humidity and makes the air very dry.

In conclusion, heating cold, humid outdoor air to 22°C can slash relative humidity from about 80% to just 12%, without removing any moisture, leaving winter air uncomfortably dry.

To preserve comfort and health (reducing mucosal dryness, irritation and pathogen transmission), a proper humidification system is essential alongside ventilation. Whether adiabatic (atomisation) or isothermal (steam injection), the right technology will restore RH to the ideal 40–60% range, creating healthier, more energy-efficient indoor environments.

The contents of this blog post regarding IAQ can be examined more in depth by reading the white paper
“Indoor air quality - Guaranteeing health and comfort in buildings”

Download the white paper

Global

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