ᐅ Cooling via underfloor heating with a ground-source heat pump
Created on: 30 Apr 2015 11:27
S
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.
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.
I believe it is important to clearly distinguish between a) actual cooling and b) preventing further excessive heating.
For a), you need an air conditioning system, while b) can be achieved at very low cost using a ground-source heat pump. As someone else already mentioned: it does affect comfort whether the average room temperature rises to 26°C (79°F) or only to 23/24°C (73/75°F).
Apart from that, I see a positive psychological effect when “cooling” is done through underfloor heating pipes. Since the floor tends to radiate coolness rather than heat, as opposed to exterior walls, a room temperature of 23/24°C (73/75°F) can feel even cooler.
For a), you need an air conditioning system, while b) can be achieved at very low cost using a ground-source heat pump. As someone else already mentioned: it does affect comfort whether the average room temperature rises to 26°C (79°F) or only to 23/24°C (73/75°F).
Apart from that, I see a positive psychological effect when “cooling” is done through underfloor heating pipes. Since the floor tends to radiate coolness rather than heat, as opposed to exterior walls, a room temperature of 23/24°C (73/75°F) can feel even cooler.
That is why there are people here in the forum who remove the enthalpy exchanger from their mechanical ventilation system in summer to keep the indoor air drier than with the enthalpy exchanger. This then complements the concept of "cooling" with underfloor heating powered by the ground-source heat pump?
These are all measures
a) Yes
b) No
Only if everything really fits together. Are the 2°C (4°F) achievable? For example, with shading, cooling via underfloor heating, controlled mechanical ventilation (or night-only window ventilation) with few windows facing south, etc.
Realistically, you achieve about 1°C (2°F) of cooling, which is hardly worth mentioning.
rick2018 has been explaining all along what the real issue is. It’s the moisture content of the air.
Air can only become drier if it is dehumidified. What people do with enthalpy exchangers in this regard is more like homeopathy. The outdoor air comes in with a certain humidity level. If no dehumidification takes place indoors, it doesn’t matter which heat exchanger is installed.
Air, like everything else, tends to balance indoor and outdoor conditions, and this equilibrium will be reached sooner or later. The capacity of controlled mechanical ventilation systems for cooling purposes is, by the way, barely enough to compensate for the heat of a television. If you dare to cook in the kitchen in summer, all your efforts will be in vain.
annab377 schrieb:
I think it’s important to clearly distinguish between a) actual cooling and b) preventing further overheating.
For a) you need an air conditioner, and b) can be ensured at very low cost with a brine heat pump.
a) Yes
b) No
annab377 schrieb:
As someone else already mentioned: it does affect comfort whether the average indoor temperature rises to 26°C (79°F) or only to 23/24°C (73/75°F).
Only if everything really fits together. Are the 2°C (4°F) achievable? For example, with shading, cooling via underfloor heating, controlled mechanical ventilation (or night-only window ventilation) with few windows facing south, etc.
Realistically, you achieve about 1°C (2°F) of cooling, which is hardly worth mentioning.
rick2018 has been explaining all along what the real issue is. It’s the moisture content of the air.
annab377 schrieb:
That’s why some people here in the forum remove their enthalpy exchanger in summer from the controlled mechanical ventilation system to keep indoor air drier than with the enthalpy exchanger. Does that complete the “cooling” plan with underfloor heating through the brine heat pump?
Air can only become drier if it is dehumidified. What people do with enthalpy exchangers in this regard is more like homeopathy. The outdoor air comes in with a certain humidity level. If no dehumidification takes place indoors, it doesn’t matter which heat exchanger is installed.
Air, like everything else, tends to balance indoor and outdoor conditions, and this equilibrium will be reached sooner or later. The capacity of controlled mechanical ventilation systems for cooling purposes is, by the way, barely enough to compensate for the heat of a television. If you dare to cook in the kitchen in summer, all your efforts will be in vain.
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