ᐅ Geothermal energy with passive or active cooling

Hello everyone!

We are considering whether to equip the brine-water heat pump (Ecoforest brand) of our geothermal system with passive or active cooling. The additional cost for active cooling over passive cooling is only €700, but we have heard the following counterargument:

The brine cooled by passive cooling already significantly lowers the temperature of the water in the underfloor heating system. The extra cooling provided by active cooling is often unusable because the temperature of the water in the underfloor heating must not be lowered below a certain limit (dew point, etc.). If in doubt, this excessive cooling will be prevented. This means that active cooling only offers benefits on the few days when passive cooling is insufficient to reach that limit temperature.

Can anyone provide input on this argument or share further reasoning for or against using active or passive cooling?

Best regards

jx7

I believe this is a strong argument here in Germany, as on warm days the humidity is usually quite high; the dew point is therefore also relatively high, and with passive cooling you often come close to reaching it. If you want it really cold, you generally need a proper air conditioning system; you can find a lot of information about that in a related thread.

From my experience, the function is, of course, not comparable to an air conditioner, but it can reduce the room temperature by about 2 degrees Celsius on hot summer days. And that difference is definitely noticeable. All of this is achieved using only the electricity needed for the circulation pump. Together with closed windows and targeted shading (blinds), we never experienced temperatures above approximately 24°C (75°F) even on extremely hot days in the upper floor.

Dew point: a certain minimum temperature specified by the manufacturers cannot be undercut. Therefore, no condensation should occur. In the bathroom and basement, I close the heating circuits anyway...