Is it possible to retrofit air conditioning if controlled residential ventilation is available?

with today's construction methods, a 3.5 kW unit should be sufficient for your living area and for the bedrooms the smallest available, preferably the 2.0 kW

At least for us, the 3.5 kW for the living area is about right (according to calculation - not estimation). For the similarly sized bedrooms mentioned here, the smallest possible 1.8 kW units were however right on the limit, which is why we decided on the next size up (2.5 kW). The outdoor unit must of course only match the calculated cooling load, which may be below the sum of the maximum capacities of all indoor units.

Yes, the KfW houses are both a curse and a blessing at the same time. You just can't get the heat out anymore, and if it's over 30 degrees for a few days, you can't get 20 degrees in the low-energy house either.
We are four people and are basically at home all day. Accordingly, in summer, it’s a constant in and out. Apart from me, no one really takes care of the shading.
Whereas I have the luxury of having KNX in the house. I just need to get around to automating the shading. :rolleyes:


Thanks for the assessment. An acquaintance installs Gree air conditioners. So I looked there. The smallest model of the series that appealed to me has 2.5 kW. But ok, then maybe for the ground floor the smaller model with 3,x kW after all.


Don’t ask. The awning was half a drama. But yes, by now we have one or actually two pergola awnings. And that was one of the best purchases. Finally shade on the terrace. :)

How does the determination of cooling capacity actually work? Is it just as exaggerated as a heating load calculation?

No one really takes care of the shading except me.

Yes. That is a crucial difference between theory and practice, which I know all too well. No arguments help here.

Apart from me, nobody really takes care of the shading.

For the design of your air conditioning system, you either have to automate the shading with KNX or not consider shading in the design. In the end, that makes a big difference.

do not consider shading in the interpretation. In the end, it makes a big difference.

No big difference??? For us, the difference between with and without shading is about 220 W/m². I find that huge, especially when you consider the usual 60 to 80 W/m² with shading.