Installing air conditioning --> KFW funding gone?

Only one indoor unit. However, we have a large airspace opposite the bedroom, so a lot of cool air flows into the lower floor, which is designed as an open space. Unfortunately, the children's area doesn't get as much. You can blow the air over during the day with a stand fan. This is not the best solution, but doable. If I were to build again, I would take a second indoor unit.

But ultimately, it depends completely on the floor plan. The controlled residential ventilation doesn't distribute much anyway and is basically switched off during the day and works at night with an open bypass.

We are also in the planning phase and also have a small airspace opposite the bedroom. I will do it just like you and think the idea is great. You say you would install a second indoor unit afterwards. Where would you put it? Children's room or ground floor? Is there anything else to consider in the planning? Do you also have 22* degrees in the children's room in summer? Then one unit would be completely sufficient for us.

I would place the second indoor unit in the hallway between the two children's rooms. Not enough cold air reaches there. We make do with a fan that blows the air across the airspace into the children's area. Since no one is home during the day, it doesn't really bother anyone, but if I could plan it again, I would do it differently. Hmm, otherwise, during the planning phase, one should also consider where the outdoor unit is installed so as not to disturb the neighbors. It is quite quiet, but some neighbors are sensitive.

I would put the second indoor unit in the hallway between the two children's rooms. Not enough cold air reaches there. We manage with a fan that blows the air across the space into the children's area. Since no one is home during the day, it doesn't really bother us, but if I could plan it again, I would do it differently. Hm, otherwise, in the planning phase, you should also consider where the outdoor unit is mounted so as not to disturb neighbors. It is quite quiet, but some neighbors are sensitive.

Ok thanks. Yes, we'll see where to put the outdoor unit. For the air conditioning to be reasonably effective, it shouldn't be too far away. Do the children's rooms get cold enough with the fan? Upstairs, we only have one children's room and an office left. If we can achieve temperatures of max. 22-23 degrees in each room with one unit, that's perfectly fine for us.

Hello everyone!

A KW40 house in prefabricated construction requires 3 times as much energy for cooling as for heating. Everything is optimized for heat retention.

When I wander through our new housing development, I notice that their north sides have no or tiny windows. That means if you only shade the direct radiation, you end up sitting in the dark.

What is the connection between these two statements?

Much more emphasis and public funding are placed on heat generation. Actually, TOO much. Because those who build 40+ mainly have surpluses with photovoltaics when they do not have to heat with it. Cooling is forgotten, postponed, or skimped on.

I am writing this here for the builders using timber frame construction, because it is particularly difficult afterwards to install lines parallel to the wall that remain invisible. That must be done early, even before the sampling.

And to the actual topic: Since cooling is done exactly when maximum solar yields are expected, the KW40 standard is not endangered.

Ok thanks. Yes, we will see where the outdoor unit will go. For the air conditioning to be reasonably effective, it must not be too far away. Do you get the children's rooms cold enough with the fan? Upstairs we only have one children's room and an office left. If we can achieve temperatures of max. 22-23 degrees in every room with one unit, that is completely sufficient for us.

Yes, the children's rooms get cold enough. Last week we had outdoor temperatures of up to 37 degrees. Inside the house it was 20 degrees (bedroom), 21 degrees (living room), and 23 degrees (children's room).

A KW40 house in prefabricated construction requires 3 times as much energy for cooling as for heating. Everything is optimized for heat retention.

I would like a source for that. Until then, I say: "Nonsense!"

The physics behind my claim:
Delta t in winter ~ 35°
Delta t in summer ~ 10°

Why the latter should require 3 times more energy with the same technology...
I go as far as to say that even with the same delta and a correspondingly designed heat pump, there should be no difference in energy demand.

On the topic: I would find it quite schizophrenic if the BAFA promotes air conditioners and then, after installation, the KFW funding is reclaimed. Both with the justification of "energy efficiency."

And since there is no Bafa police: Just have a normal air conditioning specialist install the air conditioner. For heavily insulated houses, a 2.5 kW unit in as high and central a location as possible, then run 24/7 at a low level with all doors open. Without an open staircase, a second unit (no multi-split!) must be installed on the ground floor. That won't provide 20° in every room, but about five degrees and especially 15% less humidity than before. Ergo, you can sleep again. Estimated electricity consumption for such a system: 250 kWh/year.