ᐅ Cooling via underfloor heating with a ground-source heat pump

Created on: 30 Apr 2015 11:27
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SirSydom
Hello everyone,

I am very sensitive to heat, so this will be a major focus in our new build.

In addition to an automatic shading system with venetian blinds and roller shutters, and a solid construction method, as well as a ventilation system with a bypass (and possibly a ground heat exchanger), I am considering whether "passive" or "free" cooling through the underfloor heating system makes sense. This is said to have only low operating costs since only electricity for the pumps is required. The technology also seems quite simple—a heat exchanger between the brine circuit and the underfloor heating circuit, possibly with a few valves and a mixer.

Now I am wondering if the effort is worthwhile—does it really make a difference? Does anyone have a direct comparison in the same house, once with and once without?

My wife is still quite hesitant because she fears having cold feet. "In summer, I want to walk barefoot." Is this concern justified?

Are there alternatives for cooling that won’t immediately break the budget? A separate cooling ceiling would certainly cost several thousand euros.

With a conventional split air conditioning unit, I can already hear my wife complaining about drafts, so that option is probably off the table.
Mycraft18 Feb 2020 07:18
It is more to be understood as a placebo. A noticeable effect cannot be achieved (except cold feet) because the effect does not take place where it is needed to enable effective cooling.
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Tego12
18 Feb 2020 07:52
The effect isn’t huge, but it is definitely noticeable. I would use it again because it lowers the temperature by 1 to 2 degrees (and 25 or 23 degrees Celsius (77 or 73 °F) in the bedroom can make a big difference), practically without ongoing costs. It continuously draws heat from the building’s large thermal masses (such as screed, concrete ceilings, etc.). Not a huge amount at once, but 24 hours a day, preventing significant overheating from occurring in the first place.

Of course, you can’t cool down a large, unshaded south-facing facade with this alone, but it’s a great addition that works very well in combination with good shading and can help keep a house cool.
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annab377
18 Feb 2020 08:36
@Tego12 do you have a proper vapor barrier in the ceiling, or are you just running cool temperatures through the underfloor heating? If the latter, what temperature are you keeping to avoid issues with the dew point?
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Steffen80
18 Feb 2020 09:18
Tego12 schrieb:
The effect is not huge but definitely noticeable. I would use it again because it lowers the temperature by 1 to 2 degrees (and 25 or 23 degrees Celsius (77 or 73°F) in the bedroom can make a big difference), practically without ongoing costs. It continuously draws heat from the building’s large thermal storage elements (screed, concrete ceiling, etc.). Not a large amount at once, but 24 hours a day, which helps prevent significant overheating from occurring in the first place.

Of course, it can’t cool down against a huge unshaded south-facing facade, but it’s a great addition that works really well combined with good shading and can keep a house cool.

Without costs? And the pump(s)?
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annab377
18 Feb 2020 09:32
For cooling through the underfloor heating system, you don't necessarily need additional pumps, right? And in summer, there should be enough photovoltaic output to power the pump directly. So practically without adding more pipes in the ceiling as a concrete core activation (CCA) or without extra air conditioning units.
rick201818 Feb 2020 09:38
It is still lost revenue and therefore costs that you otherwise would not have.