Heating load calculation 10.3 kW, is a 9.5 kW air-to-water heat pump sufficient?

I guess that you have a maximum heating load of 7 kW at NAT.

We have kfw70, which is the current energy saving regulation, with approximately 245m2 heating area and have an 8kw from Buderus, which unfortunately does not modulate. How you arrive at your values is not plausible to me; the heat pump sounds oversized and that will cost you, first with the higher purchase price and second with the operation. Did a heating installer recommend this combination to you?

Ps. There are now also heat pumps that run with ring trench collectors or ground drilling; these forgive configuration errors more than an air-water heat pump.

We have KfW70, which is the current energy saving ordinance, with about 245m2 heating surface and have an 8kW from Buderus which unfortunately does not modulate. How you arrive at your values is not plausible to me, the heat pump sounds oversized and that will cost you, once with the higher acquisition and secondly in operation. Did a heating engineer recommend this combination to you?

Unfortunately, I have not received the data yet. That was just the statement on the phone yesterday. He received the heating load calculation with this result and recommends this heat pump, as it is also subsidized by Bafa, among other reasons. Okay, but that means you rather think it is too big? I thought now rather that it is still too small... With a modulating heat pump, if I understood correctly, it wouldn't be so bad if it is too big, right? If it only needs 7kW, then it only runs at 7?

As far as I understand, with modulation the lower kW output is the problem, for example at 12 kW it can only modulate down to e.g. 4 kW, during the transition period it then cycles, which is bad again.

Hmm okay, but with a 9.5kW heat pump the lower range would then be okay?!

PS: I just checked the area again: heated area would be 252m² (I had forgotten a hallway and the technical room, which are also heated - even if only minimally)

Yes, even modulating heat pumps should not be oversized so that the lower modulation limit is low enough to be able to run continuously at warmer temperatures. The 10.3kW also seems high to me...