Our experience cooling with a Hybrid Heatpump: Does it actually work?

In the search for a more sustainable and comfortable home, more and more people are opting for a hybrid heat pump. These systems not only offer energy-efficient heating, but in some cases also the possibility of cooling. But how effective is this cooling function really, especially in a home that isn't optimally insulated?

In this article, as part of our Green&Money category, we share our experience with cooling using a hybrid heat pump from DeWarmte (Pomp AO) with the optional cooling function, which we’ve now used for two summers.

Our Experience Cooling with the DeWarmte Hybrid Heat Pump

We were very curious about how the cooling function would perform, especially considering the high summer temperatures we've become accustomed to. Here’s what we experienced:

Pros:

• A clearly noticeable cooling effect, especially after longer operation.

• Cooling works throughout the entire house, which feels more pleasant than the forced air of an air conditioner.

• Quiet system – no buzzing units in the bedroom.

• Low energy consumption: about 0.5 kWh per hour, which is very efficient compared to a standard air conditioner.

• No issues with dry air or drafts.

Cons:

• It takes a long time before the effect becomes noticeable – often the system has to run for 12 to 16 hours.

• Not powerful enough during extreme heat. At around 30°C outside, the system makes things a bit more bearable indoors, but not truly cool.

• Limited cooling intensity due to the risk of condensation.

• Not suitable for quick cooling, unlike an air conditioner.

DeWarmte Pomp AO with Cooling Function: The Setup

Our home is approximately 200 m², and we chose to connect a hybrid heat pump to the largest living area. The system we use is the DeWarmte Pomp AO, and we participated in a pilot program where we could test the extra cooling function before its official launch. The cooling function costs an additional €750 in total, so it’s worth careful consideration.

However, our house is not optimally insulated. The roof has old insulation, the windows and doors are first-generation double glazing, and only the cavity walls and floor have recently been re-insulated. That makes it especially interesting to see how well a heat pump can cool under these conditions. Besides DeWarmte, other hybrid pumps like Quatt and WeHeat work in similar ways, although Quatt also offers a separate solution called the Quatt Chill

Heat Distribution in the Home: Underfloor Heating

We only have underfloor heating in the house – no radiators.

• Ground floor: Tiled floor with underfloor heating.

• Second floor: Laminate floor on a wooden subfloor, also with underfloor heating.

This means that both heating and cooling are delivered through the floor.

How Does Cooling with a Hybrid Heat Pump Work?

Cooling with a heat pump basically works as the reverse of heating. Instead of extracting heat from the outside air and bringing it indoors, the system removes heat from inside the home and expels it outside. The cooling effect is then distributed through the underfloor heating system or via radiators (although radiators are less suitable for cooling).

It’s important to understand the difference between this type of cooling and traditional air conditioning. An air conditioner blows cooled air directly into a room, creating a quickly noticeable temperature drop. With a heat pump, the effect is subtler and slower. So you have to manage your expectations – and usage – differently.

Condensation: What Is It and Why Is It Important?

When cooling a room, condensation often forms on cold surfaces, especially when they fall below the dew point temperature. In the case of underfloor heating, this is a risk, as the cold floor can cause moisture in the air to condense. This can lead to wet spots, mold growth, or even damage to wooden floors.

To prevent condensation, many heat pumps automatically limit the cooling capacity. With DeWarmte, you can set the temperature yourself via the app, but they strongly advise not to set it lower than 18°C. As a result, they can’t cool as intensively as an air conditioner. This means you can’t drastically lower the temperature. The system cools slowly and modestly, but it’s energy-efficient and avoids the risk of damage.

What Do DeWarmte / Quatt / WeHeat Say About Cooling?

These companies have differing opinions, which isn’t surprising – each approaches the topic from its own perspective and commercial interest.

• Quatt claims that active cooling with a hybrid heat pump is often not cost-effective, especially in existing homes. They point out risks like condensation and moisture problems, particularly when using standard radiators or poorly insulated floors. It’s worth noting that Quatt offers its own alternative system to address these issues – so their judgment may not be entirely neutral.

• WeHeat mainly emphasizes that you shouldn’t expect air conditioning-level cooling. A heat pump provides comfort cooling: it lowers the temperature by a few degrees, which is pleasant on warm days, but limited.

• DeWarmte looks ahead to systems that enable passive cooling, such as their own HeatCycle. This approach is much more efficient and uses hardly any extra energy. Their message is clear: cooling with a heat pump is certainly possible, but only if the total system – from insulation to heat distribution – is well-optimized.

Air Conditioner vs. Cooling with Heat Pump

Here’s a direct comparison between a traditional air conditioner and cooling via a hybrid heat pump:

Feature	Heat Pump Cooling	Air Conditioner
Cooling Speed	Low	High
Noise Level	Very quiet	Often audible
Energy Consumption	Low (~0.5 kWh/hour)	High (1–2 kWh/hour per unit)
Perceived Temperature	Subtle and gradual	Immediately cold
Condensation Risk	Present	Absent
Installation Cost	€750 extra	Usually higher per room
Suitable for Entire Home	Yes	No, room-by-room
Air Quality	Natural	May cause dry air

Would I Purchase the Cooling Function Again?

That’s the big question. Looking back, I’m satisfied but not amazed. The cooling function works, is comfortable to use, and pleasant for nighttime – especially since I sleep poorly with an air conditioner blowing air. But it’s not a miracle solution.

For those with a well-insulated home, the cooling capacity may be sufficient to keep things genuinely pleasant. For us, with limited insulation, performance is decent but not spectacular. Still, we use the system often during warm days, and if we turn it on early enough, the house stays relatively cool and stable.

Given the low energy use, the comfort, and the €750 installation cost, we would likely choose the cooling function again – especially as an extra support during warm nights.

What’s the Alternative?

For another part of our home, we’ve now installed a WeHeat hybrid heat pump. There, the cooling function is included in the price. We’re curious to see how that system performs, especially since it’s slightly different. If it performs better, we’ll be sure to share our experience.

Conclusion: Cooling with a Heat Pump – Yes or No?

Cooling with a hybrid heat pump like the DeWarmte Pomp AO is a working, energy-efficient alternative to traditional air conditioners – as long as your expectations are realistic.

For those seeking subtle, quiet, and gradual cooling that uses little electricity, it’s an excellent solution. But don’t expect a “freezer effect” like with a split air conditioner. The system works best in well-insulated homes, where temperatures can be influenced gradually.

For us, it was a nice addition – especially for the nights. And even with our limited insulation, we could still achieve some cooling. And that is – especially in terms of sustainability and cost – quite impressive.