ᐅ Individual Room Control for Air-to-Water Heat Pump and Underfloor Heating
Created on: 31 Jan 2023 20:20
W
Waldbewohner
Hello,
this is more of a general question rather than related to a specific construction project.
I have increasingly heard from acquaintances that heating engineers/general contractors often recommend an electronic radiator thermostat (ERT) when heating with an air-to-water heat pump. We have also already received such an offer.
However, it seems that the whole internet is of the opinion that an ERT is not only pointless but even counterproductive.
I find it hard to judge, but the explanations sound convincing.
1) In solid construction, after a certain time, the entire space within the thermal envelope is heated to roughly the same temperature anyway. So it is pointless to turn off the heating in rarely used rooms because they are heated through the other rooms.
2) The entire masonry, screed, etc., makes the heating behavior very sluggish, and the low flow temperatures do not allow targeted "boosts." Therefore, it is more sensible to simply keep the entire underfloor heating running constantly and operate the heat pump in the "comfort range" at the lowest possible flow temperature.
3) As in point 2: increasing the room temperature at the thermostat by 2°C (3.6°F) takes many hours to become noticeable due to the sluggish system. So if it’s too cold in the evening, adjusting the thermostat doesn’t help anyway.
I am not an expert, but this sounds plausible.
Is an ERT really counterproductive and should it be avoided in solid construction with an air-to-water heat pump?
this is more of a general question rather than related to a specific construction project.
I have increasingly heard from acquaintances that heating engineers/general contractors often recommend an electronic radiator thermostat (ERT) when heating with an air-to-water heat pump. We have also already received such an offer.
However, it seems that the whole internet is of the opinion that an ERT is not only pointless but even counterproductive.
I find it hard to judge, but the explanations sound convincing.
1) In solid construction, after a certain time, the entire space within the thermal envelope is heated to roughly the same temperature anyway. So it is pointless to turn off the heating in rarely used rooms because they are heated through the other rooms.
2) The entire masonry, screed, etc., makes the heating behavior very sluggish, and the low flow temperatures do not allow targeted "boosts." Therefore, it is more sensible to simply keep the entire underfloor heating running constantly and operate the heat pump in the "comfort range" at the lowest possible flow temperature.
3) As in point 2: increasing the room temperature at the thermostat by 2°C (3.6°F) takes many hours to become noticeable due to the sluggish system. So if it’s too cold in the evening, adjusting the thermostat doesn’t help anyway.
I am not an expert, but this sounds plausible.
Is an ERT really counterproductive and should it be avoided in solid construction with an air-to-water heat pump?
W
Waldbewohner1 Feb 2023 10:40Mycraft schrieb:
@Waldbewohner
For the cooling function, however, it can make sense. Although the few degrees possible are not really cooling but at most mild tempering. Everyone has to decide for themselves if it is worth it.What would be the alternative? Is cooling (even if only by a few degrees) possible without ERR?
Probably yes, but too energy-intensive?
W
WilderSueden1 Feb 2023 11:13When cooling, you usually want all valves fully open. In our office, the building services are poorly managed, and the thermostats block the cooling. So, in early summer, we go through once and manually open all valves (meaning no regulation), then switch back to automatic in autumn.
Of course, the effect can't be compared to a proper air conditioning system, but especially overnight, it does lower the temperature by a few degrees.
Of course, the effect can't be compared to a proper air conditioning system, but especially overnight, it does lower the temperature by a few degrees.
mr.xyz1 schrieb:
And you ruin your rooms with small dust collectors on the wall.
I would leave them out and feel free. I would simply leave them out.
Who wants to see this kind of freedom...
A
akanezumi1 Feb 2023 16:18Waldbewohner schrieb:
What would the usage profile look like then?
In winter, set everything to "manual power off," as described by Michert, and in summer, only lower the temperature in the room that needs cooling?
With "manual power off," wouldn't the other rooms also get the cool water? When cooling, or better said: tempering—since it’s really only a few degrees—you need to be careful not to make it too cold. Otherwise, you can quickly run into problems with humidity (condensation) and eventually mold. The key term here is: dew point.
Also, some people find a floor that is too cold uncomfortable. Therefore, in this case, a control system might make more sense than with heating.
A
akanezumi1 Feb 2023 16:21bortel schrieb:
I would simply leave them out.
Who wants to see that exemption... When we talk about a house networked with KNX, you can always refer to a central control system if needed. I would definitely avoid the ugly individual thermostats in the rooms.
akanezumi schrieb:
I would definitely avoid the ugly individual thermostats in the rooms. Since a KNX house usually involves a more or less well-thought-out plan or even a concept, this question doesn’t really arise. The temperature sensors along with the thermostat are integrated into the push-button sensors (room controllers), so with KNX you have the ERR included. Of course, you still need the counterpart with the actuator and valve heads.
Additional individual room thermostats would make the whole project absurd and are normally not installed.
Waldbewohner schrieb:
What would be the alternative? Is cooling (even if only by a few degrees) possible without ERR?
Probably yes, but too energy intensive? Yes, of course cooling is possible without ERR and it is not too energy intensive. However, the benefit is limited both with and without ERR because the output is low. This is due to the way it works in the floor and not where the cooling is actually needed or in demand.