ᐅ Current Test Reports on Air-to-Water Heat Pumps

Hello everyone,

I am looking for recent test reports or experiences regarding air-to-water heat pumps.
On the internet, I only find test reports from 2007, which should now be outdated.

Does anyone here have information on this or can share their own experiences regarding consumption and operation (comfort, malfunctions, maintenance, noise levels)?

Thank you very much and best regards

Unfortunately, a heat pump is not like a television.
You can get a good idea by looking at the heat pump energy consumption database.

The overall quality of the entire system is crucial when it comes to a heat pump.

It was also important to me that the installer receives good support from the manufacturer and has access to spare parts. A top-quality unit is unfortunately of little use if the design is poor or if it takes days to fix a problem (or if no one shows up at all).

Domski schrieb:
With a heat pump, the overall quality of the complete system is crucial.

It was also important to me that the installer receives good manufacturer support and spare parts. Even a top device is of little use if the design is poor or if troubleshooting takes days—or worse, no one shows up.

Do you have guidelines on how such a pump should be set up—for example, regarding the supply temperature, when the electric heating element kicks in, etc.?

Do you have a reference value for how much electricity you consume per square meter (or foot) per year?

Supply temperature should be kept as low as possible, which requires the underfloor heating system to be properly designed. No buffer tank, and if possible, no additional heating system. Everything else depends on individual circumstances.

My system is not suitable as a reference because it operates as a bivalent system with a fireplace.

Hans-Maulwurf schrieb:
Do you have any values for how such a pump should be set, regarding flow temperature, when the electric heating element switches on, etc.?

Do you have a reference value for how much electricity you consume per square meter per year?

Domski has covered all the essential points. Here are a few additions and example values:

The required flow temperature is not a setting on the heat pump. You need to plan the underfloor heating early on so that the house heats efficiently at the lowest possible flow temperature, tailored individually. Each room is planned separately. For the bathroom, this usually means a water-based wall heating system (not just a towel rail) and/or electric supplementary heating if higher temperatures are desired permanently (water-based) or temporarily (electric).

A value below 30°C (86°F) at standard outdoor temperature should be targeted as the maximum flow temperature in a new build. All circuits should be around 80 meters (260 feet), allowing a maximum deviation of 20%.

The heat pump should be selected according to the heating load, should be modulating, and not oversized. The electric heating element should not be planned as part of the system.

You cannot change the underfloor heating later, and it is more important than the heat pump.

Electricity consumption in a KfW 55 house with controlled ventilation depends on the location: when everything is done correctly, around 10 kWh of electricity per square meter (m2) of living area (not usable area) per year is realistic. With poor planning and/or operation, consumption can be up to four times higher. This can mean about a 1000€ difference per year for a typical single-family house.

Unfortunately, tradespeople are usually not the right partners for planning in your favor.