Cooling via underfloor heating with brine heat pump

... I have a question about that. You can also "send" the intake air of the controlled residential ventilation through a pipe system buried in the ground. I know that only makes sense if you cannot cool via the brine pump; it would also make sense in winter because the cold air is slightly pre-warmed. The background of my question: we cannot install a deep brine heat pump; natural gas is available on the property, and the connection will cost around €1000, so from my point of view, almost all other heating systems are currently excluded for economic reasons (but: I haven’t calculated it through to the end yet).

Best regards

So, I’ll provide an interim report. Our cooling system is now running even at these temperatures. We set it to 20 degrees. We are all still walking around barefoot here. However, most rooms have parquet or cork flooring. Only in the hallway, bathrooms, and kitchens do we have tiles, which at these high outdoor temperatures is not unpleasant but rather a nice cool refreshment. It is really pleasant here in the house, and we don’t want to go outside.

Hello, I’m reviving this topic.

The reason is that we want to get a modulating brine heat pump (either trench collector or geothermal drilling), which can also be used for cooling in summer (this not only has a positive cooling effect but also contributes to faster and better regeneration of the soil, especially with the trench collector).

The flow temperature of the underfloor heating pipes should not be set colder than 19 °C (just as a rough value) due to the dew point issue. In addition, a controlled residential ventilation system is advisable (due to the moisture removed from the room).

Now my question: in the pink forum, there is a strong tendency to install a few additional pipes in the filigree concrete ceiling in order to use concrete core activation.

But this costs more (I know, not much if you install it yourself) and is simply a bit more effort (I know, this is also limited) and maybe even a structural issue of the concrete ceiling. And I know that you can actually cool better via the concrete ceiling than via the floor. Now I would like to know: is the floor really uncomfortable in summer with about 19-20 °C flow temperature or is it perhaps even pleasant and contributes a small part to the cooling (not heating up significantly in the first place) of the building?

Would you do cooling via the underfloor heating pipes using the brine heat pump again and other forum users? Or would you invest the costs and effort in the CCA in the ceiling because 20 °C cold tiles in the bathroom are uncomfortable or other reasons speak against it?

Thanks for your opinions.

It is not proper cooling, rather buffering. A proper air conditioner is the method of choice. Cooling through the ceiling and walls makes more sense. For the money, however, you can also install fancoils or split units...

No, we don’t want proper air conditioners/devices. Yes, it might not be true cooling, but on the other hand, maybe it is? If the bricks of the house are 25 degrees in midsummer and the floor is "only" 20 degrees, that already contributes somewhat to cooling the air temperature (even if only minimally). But since not all sides of the room radiate warmth, and the floor is rather cool, one definitely perceives it as cooler than without a cooling brine heat pump, right? You say ceiling or wall would be better – yes, but how much does that really make a difference and why exactly?

The dew point issue is not as pronounced on the ceilings and walls, and you have plenty of additional surface area. Thus, you gain additional cooling capacity. With cooling at the floor, you can buffer 1-2°. During a long heat period, when the masonry has been heated through, the cooling capacity is no longer sufficient to cool noticeably. Only the feet are cold. Also important is the dehumidification achieved with an air conditioner, which strongly influences the perceived temperature. This effect is also missing in your case. The controlled residential ventilation does not really dehumidify. In summer nights, the bypass runs, and presumably during the day it is off, otherwise the house would heat up further. Overall, better than nothing, but do not expect miracles.