ᐅ Using a geothermal basket to precondition the air for a mechanical ventilation with heat recovery system?

@TmMike_2
We are building a KfW40 house using timber frame construction. Since we will definitely have good shading and, in general, will pay close attention to other conditions (windows closed, etc.), I am currently mostly only a little concerned about the warm outside air being drawn in. And here is exactly the point: if you can pre-cool this air with little effort, that sounds like THE solution... But I have no idea how much effort that would actually require.

Well, timber framing is basically the opposite of solid construction, so I don’t have personal experience with that.
Instead of your cooling trench, I would recommend a split air conditioner on the upper floor, at least for the bedrooms and possibly an office.
I initially wanted to cool through the floor, but I imagine that would feel unpleasant when walking on it. If you want to have 20°C (68°F) indoors, the floor would need to be at least around 15°C (59°F).

I also wanted to build something like this but had concerns. Cooling warm, humid air underground leads to moisture and therefore to mold or mildew. The air would probably also need to be filtered and possibly soundproofed.

In der Ruine schrieb:

I also wanted to build something like this, but I had concerns. Cooling moist warm air underground leads to moisture and therefore to rot or mold. Then the air should probably also be filtered and, if necessary, soundproofed.

At the very least, it’s not enough to just bury 30m (100 feet) of sewer pipe 1m (3 feet) underground.

The more I read, the more I believe that a geothermal basket is quite different from an air shaft. I cannot see a snorkel in any illustration online...

Yes, a geothermal basket is usually connected to a brine-to-water heat pump, right?

TmMike_2 schrieb:

Well, timber framing is basically the opposite of solid construction, and I have no personal experience with that.
Instead of your cooling trench, I would suggest installing a split air conditioning system on the upper floor. At least for the bedrooms and possibly the office rooms.
I initially wanted to cool through the floor, but that seems uncomfortable to me in terms of how it feels underfoot. If you want the indoor temperature to be around 20°C (68°F), the floor would need to be at least 15°C (59°F).

Of course, floor cooling does not replace an air conditioner. The full comfort improvement can only be achieved by the latter.
However, floor cooling can indeed be “effective” within its limited scope and still provides noticeable comfort benefits. At least that has been our experience and the feedback from all visitors who have been in our home...

We also dislike cold floors, so we have parquet flooring throughout the house (except in the bathrooms).
The cooler wood generally feels pleasantly cool rather than too cold. Ultimately, this is just a matter of relative perception, because the floor should not actually get too cold, at least not like in your example.
The floor temperature should not be more than 5-7°C (9-13°F) below the room air temperature to prevent condensation. So, if my target room temperature is about 23.5°C (74°F) and the room heats up to 28°C (82°F), then the floor temperature would be around 21°C (70°F), helping with cooling. This, of course, only works with “continuous operation” and as a preventive measure, so the automatic temperature control prevents the room from warming up in the first place. It is ultimately also “limited,” but with indoor temperatures of 23-25°C (73-77°F) during outside temperatures above 30°C (86°F), we are quite satisfied.