ᐅ Is it worth preparing for air conditioning installation?

Regarding the initial question: I would install a small (2.5 kW) unit in a high, central location in the house during construction.

If you let it run as soon as the room temperatures start to get too high and only turn it off when the heat phase is over, you just need to keep the doors open and you will have pleasant humidity throughout the entire house and—especially in a new build—comfortable temperatures as well.

Of course, it is better to have a unit in every room, but that eventually becomes very expensive.

Deliverer schrieb:

Why should an air conditioning system reduce a building's energy efficiency? They are supported by the Bafa because they IMPROVE the energy efficiency of buildings.

Do you have any evidence for that? We were told that a controlled residential ventilation system with air conditioning function (inverter) will compromise our KfW55 requirements.

"According to the definition in § 3 paragraph 1 no. 31 of the Building Energy Act, the calculation of 'heat and cooling energy demand' only includes heat and cooling demands for heating, domestic hot water, and cooling. Electricity requirements for, for example, auxiliary energy, ventilation, and lighting are not considered. The heat and cooling energy demand therefore refers to the amount of energy needed annually to cover the building-related heat and cooling demand for heating, hot water production, and space cooling, including the thermal effort for transfer, distribution, and storage." (p. 67, - List of technical FAQs - BEG WG / BEG NWG - Efficiency houses / efficiency buildings)

And since air conditioning systems require a lot of electricity, this is also factored (negatively!) into the building’s energy value. That’s at least how I understand it.

Well, if there is no official cooling energy demand, it might be a ventilation and auxiliary energy demand and therefore not taken into account? I would be more concerned about the additional thermal bridge caused by the pipe penetration. Not all contractors may be equally careful with that...

To what extent is the air conditioning actually necessary? Shouldn’t it depend on how much the house heats up during the summer months? If the energy consultant calculates that I don’t need air conditioning, then everything should be fine. The same applies to heating demand. If I want to heat the house to 30°C (86°F) instead of the standard temperature and therefore choose a larger heater, the KFW shouldn’t have an issue with that, right?

Here are the details regarding the Bafa program:
"The funding program for cooling and air conditioning systems supports the use of climate protection technologies in commercial applications. Split and multi-split air conditioning units are not eligible for funding under this program, and private individuals are not eligible to apply. Split and multi-split air conditioning units can (...) be supported as heat pumps. The requirement is that they are primarily used for space heating – an additional air conditioning function is essentially a ‘side benefit’ of the funding."
-> This is not about direct or intentional funding but rather a kind of "carry-over effect" for air conditioning.

That wasn’t the point of the last question. The question was whether installing an air conditioning system alongside the heat pump could negatively affect achieving a KfW standard.