ᐅ Is it worth preparing for air conditioning installation?

Bauenaberwie schrieb:

Unfortunately, yes. In the past, energy consultants probably looked the other way, but that is no longer possible. Up to two devices can be covered by a photovoltaic system; from the third device onward, you lose all funding. Since we are currently in the planning phase ourselves, these are reliable statements at least for a 55 standard house. We will probably only lay the wiring initially and then wait through the first summers. If it really becomes unbearable, we will consider installing the devices anyway.

Hmm, in that case, I have to say I don’t understand the calculation. Isn’t the sequence as follows:
1. I have a house with certain characteristics.
2. Based on this house, I determine the heating and cooling demand.
3. According to the heating and cooling demand, I choose the heating and cooling systems.
4. With the chosen heating and cooling systems, I can determine the renewable energy (RE) class.

If in step 2 no cooling demand is identified, why should this affect the RE class?
It’s, of course, a different matter if the calculation identifies a cooling demand, but if there is none?!

pagoni2020 schrieb:

I can only speak from recent experience that simply installing the air conditioning would have ruined our KfW standard. We had exactly this problem 8 weeks ago.
The energy consultant recalculated the building under this condition according to a different standard (at least that’s how I understood it), and initially it was NOT sufficient; but eventually, according to him, it was, although he said this recalculation was absolutely necessary.

May I ask how much your energy consultant charged for this "recalculation"?

€300 gross (Words Words Words Words Words)

pagoni2020 schrieb:

€300 gross (words words words words words)

That’s possible, but maybe just air conditioning directly 😀

Deliverer schrieb:

Regarding the original question: I would install a small (2.5 kW (8500 BTU)) unit in a high, central location in the house during construction.

If you run it once the room temperatures get too high and only turn it off after the heat period is over, you just need to keep the doors open and you have comfortable humidity and – in a new build – also comfortable temperatures throughout the whole house.

Is that based on actual experience? Does it really work?

I have seen statements like this here a few times, and actually, this could be a feasible scenario for me for retrofitting. I could install the outdoor unit on the flat roof without major modifications, use an existing penetration, and place an indoor unit in the upper floor hallway, mounted on a wall facing the adjacent room. Drainage is not a problem in that adjacent room, and the roof penetration is accessible. So, it’s actually quite straightforward.

I have installed this system in two houses (one older building, one new build). I can share floor plans and/or photos via private message if you want to get a better idea.

You also need to differentiate: Do you want unconditional air conditioning, or is it enough for you to keep your apartment or house comfortable and ensure restful sleep at all times?

If you go with the latter, it helps to install the indoor unit somewhere elevated. If all ceilings are the same height, a somewhat central location is preferable. Depending on the layout, this can work better or worse. For example, I cool my (older building) living room, which is connected by an 8-meter (25-foot) long corridor to three bedrooms. So it’s a really unfavorable layout for this type of cooling. Still, the effect in the bedrooms is enough to sleep well under a light blanket even during the peak of summer. Without air conditioning, this was often impossible for weeks. The temperature difference between the coldest and warmest areas is a maximum of 3°C (5°F), usually only 2°C (4°F).

The most important thing, as mentioned, is the operating time. It’s no good to come home from work and cool the place down in 15 minutes. A single unit like this will run for a long time, and during the height of summer it can run continuously. This also allows the air to circulate throughout the entire home. There’s no need to worry about electricity consumption. Usually, it runs at about 300 watts. On hot days of 35°C (95°F), it might spike to 800 watts. But for the (to me) incredible luxury, I am happy to spend around 150 euros a year. Since last year (with photovoltaics), it may only cost about 50 euros.

Edit: Additionally, for someone who always keeps all doors closed, this method isn’t really suitable. And as another tip: you don’t lose much by simply giving it a try and upgrading later if you don’t like it. It’s generally recommended not to use multi-split systems. They are less efficient, more expensive, less flexible, and don’t offer redundancy. Unlike heating systems, which always break down on December 24th, air conditioners always seem to fail on July 31st. ;-)