Experience with reversible operation of the heat pump

But one point to consider: the cooling function of an air-water heat pump negatively affects the overall balance, and thus the KfW40 standard might no longer be met

Hopefully, that shouldn't play a role in our house. It already undercuts the KfW40 requirements without a photovoltaic system, so with the 7 kWp on the roof, there should (I'm not an expert) still be enough "room" to improve.

Unfortunately, it is not a simple matter of adding "+" points and "-" points. Therefore, that would be too general. I would estimate the chance that your Kfw 40 house would then only be a KFW 55 house as 50:50.

We decided against the cooling option just yesterday because it is too expensive for the play stuff that it is. For us, a total of about €5000 would have been incurred for the additional module of the system, other room thermostats, and necessary protective measures against condensation. We now want to inquire about what might possibly need to be prepared in order to easily install a "real" air conditioning system in a few years.

5000€? The surcharges I know of are always between 800 and 2000... if it's 5000, they're trying to rip you off.

We paid a surcharge of 1100€ at Stiebel Eltron, including dew point monitoring. Now, during the hot days, it was worth gold, keeping the house at 23-24 degrees (of course including good shading), and almost without any additional costs. But I wouldn’t pay 5000 either....

Hello,

I just registered here, especially because this question concerns us as well. Therefore, I would like to ask again about experiences with the cooling function of heat pumps via underfloor heating. I could imagine that a simple fan might counteract the air stratification.