Air conditioning: What is the royal way

that will be even more expensive than. Split but is then cheaper in operation

If you want to implement photovoltaics anyway, the costs will definitely be limited. You have already described that. Therefore, for me, the best option. Otherwise, be careful when building the house. I would then build with sand-lime brick, rock wool, and clinker. Additionally, forego a lived-in attic and place the bedroom facing north. Also, of course, work with the shading of window areas. That should actually be enough.

If you want to implement photovoltaics anyway, the costs will definitely be manageable. You have already described that. Therefore, for me, the best option. Otherwise, be careful when building the house. I would then build with sand-lime brick, stone wool, and clinker. Additionally, do without an inhabited attic and place the bedroom facing north. Also, of course, work with shading of window areas. That should actually be enough

Problem: In the height of summer... living room -> terrace -> garden... kids in and out in and out...

You can insulate however you want... the place will be warm. I just let the AC run... and keep the terrace door open. Done. Just like the Americans do...

I have previously planned a "normal" split system with an outdoor unit and 3 wall units and prepared quite a bit for it. Now I’m not so sure it makes sense anymore, because unlike the old house (timber frame), we no longer have this overheating on the upper floor. A 52mm wall structure really does help. Let’s see how things develop when it gets really hot for a longer period. I can place the outdoor unit on the garage roof and route through the attic into the three potential bedrooms on the upper floor. I would recommend this as preparation to everyone.

I have thought the following for myself:

1: This summer has not been really hot yet. The last one wasn’t either. Two and three years ago, we had nearly 40 degrees for days. Then we talk again with people who have well insulated their homes - there is nothing left to insulate, but the heat is simply inside and can then only be partially vented out without air conditioning. However, the thick insulating masonry helps to release the stored heat more slowly.

2: Ceiling or floor cooling only creates small temperature fluctuations (also because condensation must not form). Therefore, it is not very effective if the house is regularly left open.

3: Cooling through ventilation doesn’t work because the air volume is way, way, way too low.

4: Air conditioning costs electricity, that’s true. The following can be calculated: a 10kw system is sufficient for the bedroom, 2 x children’s rooms, and the living room. The 10 kw are roughly calculated with an efficiency of 4. Added to that is a simultaneity factor of about 0.4 on average (meaning only 40% load because rarely everyone is at home). If I now calculate 1000 operating hours, I get:

1000h x 10kw : 4 efficiency x 0.4 simultaneity factor = 1000kw x 0.21 Euro = 210 Euro im Jahr -> that is therefore less than 20 Euro per month. What are you willing to pay for a cool place at 40 degrees?

5: The 1,000 hours include heating phases. The next advantage of air conditioning is that it not only cools quickly and efficiently, but also heats quickly and efficiently.

The system costs us just under EUR 9,000 gross.

Anytime again!

So I find the calculation method interesting and comprehensible. I also consider it reasonable in terms of price. On hot days, you wish for that too. So maybe on 7 days a year. For those who want it, the air conditioning is actually the right thing, I think.

I have a moderately insulated old building and in recent years I never had more than 26/27 degrees. Still very very warm, but compared to 40 degrees quite bearable.

The air conditioning is plenty of luxury. Personally, it’s not worth the money to ME. At least not with a limited budget. If I absolutely want a way to cool down, that would probably be the effective means.