Current test reports air-to-water heat pump

Unfortunately, that doesn’t really help you much, but I’ve read a few tests and often they only include a small selection of devices. For example, I just got a recommendation from a colleague to take a look at Rotex and Tecalor. The parent company of Tecalor is the market leader in the field of air conditioning technology, and an air-to-water heat pump comes from air conditioning technology. I have never seen these companies in the tests so far.

I am currently also looking for a good air-to-water heat pump, but that is very difficult. The manufacturers refer to the craftsmen, and they know about heating systems, but not about air conditioning units. So far, no one has been able to explain to me how an air-to-water heat pump works. The usual answer is something like a refrigerator, just the other way around. Aha… And why is there refrigerant? Which refrigerant does the air-to-water heat pump use? No one knows that the current refrigerants are banned and that the much more environmentally friendly R-32 will be used in the long term. For this top advice, the companies want 11k for an air-to-water heat pump that is delivered on the market for 6k.

When I now read that the underfloor heating is even more important, I am all the more desperate because that will fall back on us again. I will make another appointment with the energy consultant. He seemed competent and might be able to do the necessary calculations for me, or how would you proceed?

Unfortunately, that doesn't help you much, but I have read a few tests and often there is only a small selection of devices. For example, I just received a recommendation from a colleague to take a look at Rotex and Tecalor. The parent company of Tecalor is the market leader in the field of air conditioning technology, and an air-to-water heat pump comes from air conditioning technology. I have never seen these companies in the tests so far.

I am currently also looking for a good air-to-water heat pump, but that is very difficult. The manufacturers refer to the craftsmen, and they know about heating systems, but not about air conditioning units. So far, no one has been able to explain to me how an air-to-water heat pump works. Mostly the answer is something like a refrigerator, just the other way around. Aha... And why is there refrigerant? Which refrigerant does the air-to-water heat pump use? No one knows that the current refrigerants are banned and that in the long term the significantly more environmentally friendly R-32 will be used. For this top advice, the companies then want 11k for an air-to-water heat pump that is delivered for 6k online.

When I read now that the underfloor heating is even more important, I am all the more desperate, because that will fall back on us again. I will make an appointment with the energy advisor again. He seemed competent and maybe he can do the necessary calculations for me, or how would you proceed?

Don't try to find the best heat pump. Take the one that your construction company, your GWS knows at least somewhat, or at least has the responsible technician on speed dial. So, the one he suggests to you.

Then make sure that the installation spacing of the underfloor heating is appropriate. And that the heating load of the heat pump matches what is stated in your KFW report. No heating storage tank and no bypass valve.

Once everything is installed, you unscrew the actuators from the controllers in the hydraulic balancing valve (HKV) and turn off the thermostats, switch the hysteresis from "gas heating" to "heat pump", set the hot water to 41 degrees instead of 60, and keep adjusting the heating curve until it fits. Then you still swallow hard once because there is really still a lot of water in the new building and pay 200€ advance for electricity, and look forward to the following year...

Procedure:

1. Underfloor heating:
a. discuss individual comfort temperatures (especially bathroom, does it have to be 24°?) for each room
b. have the room-by-room heating load calculated according to DIN, using the exact U-values of the house
c. have surface heating planned to achieve the comfort temperature with a low flow temperature. All circuits approx. 80 meters, no mini or maxi circuits accepted.
d. submit plans to the heating engineer

A good heating engineer can of course do this himself. It is safer if it is done separately.

2. Selection of heat pump and specialist company:
a. modulating heat pump: this way you get, among other things, a somewhat modern device
b. under no circumstances a combined unit with room ventilation, air-to-air or exhaust air heat pump
c. no buffer, no solar thermal, no water-bearing fireplace, no bypass valves, hot water storage with a large heat exchanger (2-3m²), 200-300l
d. sizing: use the heating load without surcharges from the room-by-room calculation including ventilation losses as a basis. If there is particularly high hot water demand, possibly calculate separately. Do not use the heating load from energy or KfW certificates.

If you find a heating engineer who agrees to this, then that’s the whole thing.

I would choose a compact unit instead of split, because that reduces complexity and possibly follow-up costs during replacement as well as maintenance costs – but it’s not a must.

In conclusion: it is significantly more important to avoid typical mistakes in planning and hydraulics than to find the "best" heat pump. Therefore, one should read up and not blindly trust the heating installer or manufacturer. There are enough articles about this in other forums and on the internet.

Thank you very much for the detailed answers. I have to honestly say that the topic of heating is quite intimidating. As a complete layman, figuring it out to avoid ending up paying 400 euros per month for electricity will be difficult.

I don't understand that either....there are tests for every little thing....you can even look at reviews for doctors, but not for an air-to-water heat pump costing 11k.

We took the one our heating technician recommended to us and first visited a few people who had installed it and asked if there were any problems and listened to the unit....it could also be very loud if the device is bad....