Against the backdrop of Europe’s energy crisis and increasingly ambitious decarbonization targets, energy saving and CO₂ reduction in the HVAC (heating, ventilation, and air conditioning) sector have become urgent issues for manufacturing facilities such as factories and warehouses.
From a whole-building perspective, approximately half of total energy consumption is attributable to heating and cooling, and HVAC systems alone account for about 38% of a building’s energy use. It is also widely reported that poor operation and control can result in as much as 20% of HVAC energy being wasted. In addition, electricity prices in Europe have risen sharply in recent years, increasing by more than 300% compared with 2016.
Under these conditions, improving HVAC efficiency to reduce operating costs and CO₂ emissions has become a critical challenge for manufacturing facilities across Europe, including Central and Eastern Europe (Hungary, Poland, the Czech Republic, Slovakia, and neighboring countries).
This article provides an overview of practical HVAC operational improvements, energy-efficient technologies, and real-world examples relevant to manufacturing sites.
Examples of HVAC Operational Improvements
We begin with low-cost energy-saving measures achieved through better operation of existing equipment. Even improvements that can be implemented quickly and without major investment can deliver meaningful energy reductions.
- Optimization of temperature setpoints Reviewing room temperature setpoints and allowable temperature ranges is a fundamental energy-saving measure. Studies have shown that adjusting setpoints appropriately according to season and operating conditions can significantly reduce energy consumption. In many cases, relaxing cooling or heating setpoints by just 1°C can reduce power consumption by several percent. Expanding temperature deadbands within acceptable comfort limits is therefore recommended.
- Optimization of operating schedules and staggered start-up Reviewing start-up and shutdown schedules for air handling units and chillers, and operating them only when necessary, is another effective approach. “Optimal Start/Stop” control and staggered start-up (rather than simultaneous start-up of multiple units) can help reduce peak electricity demand and eliminate unnecessary operation. During nights, weekends, and holidays, relaxing temperature settings or stopping part of the system can further prevent energy waste.
- Thorough cleaning of filters and heat exchange coils Clogged air filters and dirty heat exchanger coils reduce airflow and heat transfer efficiency, increasing energy losses. Regular cleaning can reduce the load on fans and pumps and improve overall efficiency. In one study, cleaning HVAC systems resulted in an average reduction of 41–60% in fan and blower energy consumption. In particularly severe cases, cleaning heavily contaminated coils increased supply airflow by 110% compared with the pre-cleaning condition. These results clearly demonstrate that regular maintenance of filters and heat exchangers is essential for maintaining HVAC efficiency. https://www.facilitiesdive.com/news/hvac-cleaning-improving-indoor-air-quality-energy-efficiency-ventilation/743084/
- Use of night purge (night-time outdoor air cooling) Night purge is an effective method in which heat accumulated indoors during the day is removed using cooler outdoor air at night, thereby reducing cooling loads the following day. By pre-cooling the building during night-time or early morning hours, the energy required for HVAC system start-up can be significantly reduced. Often referred to as “free cooling,” experts consider both free cooling and night purge to be key strategies for reducing HVAC energy use. This approach is particularly well suited to the Central and Eastern European climate, where large temperature differences between day and night are common.
These operational improvements can typically be implemented without capital investment and within a relatively short timeframe, making them ideal first steps. Next, we turn to technical approaches for further efficiency gains.
Equipment and Technologies for Improving HVAC Efficiency
In addition to operational improvements, the adoption of high-efficiency equipment and advanced technologies is accelerating efforts to reduce energy consumption and decarbonize HVAC systems. Below are examples of practical solutions for manufacturing facilities.
Upgrading to high-efficiency heat pumps Replacing fossil-fuel boilers or outdated chillers with high-efficiency electric heat pumps is an effective way to improve heating efficiency while simultaneously reducing CO₂ emissions. Heat pumps extract thermal energy from outdoor air or waste heat and can deliver several times more heat than the electrical energy they consume. As a result, they offer substantial energy savings, especially for heating applications. Across Europe, many factories and warehouses are transitioning to heat-pump-based heating systems, with numerous examples showing significant reductions in both heating costs and environmental impact. A representative example is Daikin’s new factory near Łódź, Poland. The facility employs a comprehensive energy-efficient design combining high-performance electric heat pump heating, cold-climate hybrid HVAC systems, waste heat recovery, and integrated control of HVAC, ventilation, and lighting through a building management system (BMS). By efficiently utilizing outdoor air as a heat source, the system replaces fossil-fuel boilers while maintaining flexibility for cooling operation in summer. This advanced design was recognized with the 2025 Polish Green Building Award, making it a leading example of decarbonization and energy efficiency in industrial facilities.
Utilization of free cooling (outdoor air cooling) Free cooling uses outdoor air as a cooling source during seasons when ambient temperatures are lower than the process or comfort cooling requirements. In practice, an outdoor heat exchanger (free cooler) is integrated into the chiller circuit. When outdoor temperatures fall below a defined threshold, compressors are stopped or partially unloaded, and circulating water is cooled using only outdoor air. In Europe’s cold climate, this “free” cooling can be used for extended periods from autumn through spring. Equipment suppliers report that, depending on location, electricity consumption can be reduced by up to 80%. In the UK, for example, partial or full free cooling operation is possible during most of the period from October to April, resulting in significant energy savings. Another advantage is that free cooling units can often be retrofitted to existing chiller systems, making them a cost-effective solution with relatively short payback periods. A concrete example comes from a UK CNC precision parts factory, where aging small chillers were consolidated and replaced with an ICS Cool Energy air-cooled chiller (approximately 133 kW cooling capacity) combined with a 140 kW free cooling unit. As a result, cooling energy consumption was reduced by 71%, achieving annual electricity cost savings of approximately GBP 17,500 under 24-hour operation. The payback period was estimated at around nine months, with additional savings achieved through inverter-controlled fans. In another case supported by the same supplier, a chemical plant replaced its bead mill cooling system with three high-efficiency chillers and a 360 kW free cooling configuration, reducing annual energy consumption by 42% and achieving payback within six to nine months. These examples clearly demonstrate the strong energy-saving potential of free cooling.
https://www.icscoolenergy.com/news/chillers/lower-energy-costs-free-cooling/
Use of moisture recovery (total heat recovery ventilation) By introducing moisture-recovery heat exchange ventilation systems (HRV/ERV), it is possible to recover not only sensible heat but also moisture (humidity) from exhaust air. This allows outdoor air to be pre-heated or pre-cooled while maintaining appropriate humidity levels. As a result, problems such as excessive dryness in winter or excessive dehumidification loads in summer can be mitigated, significantly reducing overall HVAC energy consumption. According to Eurovent (2025), moisture recovery provides greater HVAC load reduction than conventional heat recovery alone. In Central and Eastern European manufacturing facilities with high heating demand, moisture recovery contributes to both reduced ventilation energy losses and improved comfort and product quality.
Key Points for Facility Managers to Consider First
HVAC energy-saving measures cover a wide range of options, but from a practical standpoint, a step-by-step approach is essential. For many manufacturing facilities, the following order of action is realistic and effective:
- Operational improvements (review of temperature setpoints, optimization of operating schedules, cleaning of filters and coils, etc.)
- Additions or retrofits to existing equipment (free cooling, heat recovery ventilation, additional control functions, etc.)
- Equipment renewal (replacement with high-efficiency heat pumps, BMS integration and advanced control, etc.)
In practice, many factories can achieve energy savings of approximately 10–30% through measures in steps ① and ② alone.
In Central and Eastern Europe in particular, it is not uncommon to find that:
- Existing HVAC and heat source equipment has been in operation for 10–20 years or more, and
- Chillers and AHUs are mechanically sound, but control systems remain outdated.
In such cases, significant energy savings can often be achieved without immediate replacement of major equipment. By improving operating methods, upgrading control strategies, and implementing additional measures such as outdoor air utilization and heat recovery, meaningful efficiency gains can be realized with relatively modest investment.
As a first step toward HVAC energy efficiency, facility managers should focus on understanding current operating conditions and control systems, and then proceed from the perspective of “changing how the system is used” and “unlocking underutilized functionality.”
