Systemair on Why Natural Refrigerants ‘Will Hit Hardest’ in Integrated HVAC Systems

Menerga is currently developing HVAC systems around natural refrigerants, and CO₂ is the main one in our latest heat pump. The CO₂mpass platform puts an air-handling unit and an integrated CO₂ heat pump into one system, built for heating, cooling, ventilation and, depending on the job, dehumidification and heat recovery.

It’s a good fit for swimming pools, wellness centers and other buildings that need heating and cooling at the same time. CO₂mpass isn’t one fixed heat pump: It’s a range covering different applications and capacities. A lot of the focus goes into making good use of the recovered heat at different temperature levels. In a pool application, for example, that recovered heat can go toward heating the air, the pool water and domestic hot water.

Demand is coming mostly from applications that use a lot of energy and have a real need for heat recovery. Pools are the clearest example – they need constant ventilation and dehumidification, plus heating for the air, the pool water and domestic hot water, all at once. Beyond that we’re seeing demand from hotels, wellness facilities, hospitals, commercial buildings and industrial sites. Interest in natural refrigerants has grown noticeably over the last three to five years.

Higher energy costs, decarbonization targets and the tightening f-gas rules in Europe are all pushing that. The retrofit side is picking up too: A lot of existing plant rooms and HVAC systems across Europe are getting old enough to need modernizing, and swapping older HFC equipment for a natural refrigerant system solves both the regulatory issue and the efficiency issue simultaneously.

Regulation and efficiency are the two biggest ones right now. The f-gas rules are steadily cutting down what high-GWP refrigerants can be used for, so refrigerant choice is something you have to think about early at the design stage, not after.

Efficiency matters just as much. CO₂ works especially well where there’s a demand for cooling and high-temperature heat at the same time. The transcritical CO₂ process can pull heat out at different temperature levels and, depending on the application, get water up to around 70°C [158°F]. On top of that, sustainability targets, running costs and how long the equipment needs to last are all pushing building owners to look harder at natural refrigerants.

The big one is pressure – CO₂ systems run at much higher pressure than conventional HFC systems, which raises the bar on component selection, design, installation and commissioning. There’s also a knowledge gap since a lot of designers and installers built their experience around conventional refrigerants over many years.

The fix is mostly technical education and hands-on experience. You can’t just treat CO₂ as a drop-in replacement for an HFC. It has to be designed around it from the start. At Menerga we’re closing that gap through our own product development, testing and commissioning work. Using our own production site to install the CO₂mpass 35.20 lets us get real operating experience and feed it straight back into product development.

We treat both as relevant options. Which one makes sense depends on the application: available space, redundancy needs and how the heat pump has to tie into the rest of the HVAC system. We’re not just chasing bigger nominal capacity on a single unit. The real focus is a scalable system concept that can flex to what the project needs. For Menerga, that means integrating with the air-handling system so the whole thing works as one energy system rather than treating the chiller or heat pump as something standalone bolted on.

Two things we’re keeping a close eye on are refrigerant regulations continuing to tighten and the growth of the European retrofit market. The two are tied together. A lot of existing HVAC installations were built around refrigerants and technology that are getting harder to justify keeping over the equipment’s lifetime.

That’s creating demand for solutions that hold up not just today but years down the line from a refrigerant standpoint. Our development work is built around natural refrigerants, better system efficiency and flexible integration into existing HVAC setups. Retrofit capability is only going to matter more since Europe has a huge base of existing systems that will need modernizing in the coming years.

We think natural refrigerants will hit hardest in integrated HVAC systems – cases where heating, cooling and ventilation are currently handled by separate equipment. Pools already show what’s possible since they need cooling/dehumidification and heating at the same time.

The next step is treating the heat pump as part of one integrated energy system where heat pulled out of one process gets recovered and reused elsewhere instead of just being thrown away. That can cut both energy use and the number of separate systems a building needs. We see a lot of room for this in hotels, wellness facilities, hospitals, industrial buildings and retrofit projects.