ᐅ Individual Room Control for Air-to-Water Heat Pump and Underfloor Heating

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?

Have some installed, as they are required by the energy saving regulations. Make sure you can set them to "manually off" without electricity. Once you have moved in, set them all to "manually on" and you won’t need to adjust the rotary controls on your wall ever again.

And you spoil your rooms with small dust catchers on the wall.
I would skip them and get a professional cleaning service.

In combination with “smart” home systems, such as KNX, I wouldn’t want to do without it! Even if you want to “cool” with underfloor heating, using ERR can still be quite useful.

RotorMotor schrieb:

When it comes to "smart" home systems like KNX, I wouldn’t want to do without it! Even if you want to "cool" with underfloor heating, using an ERR can definitely make sense.

I don’t understand how having a KNX installation influences the decision whether an ERR is generally useful. It’s just another way to control things.

When it comes to a cooling function, the situation may be different. In that case, an ERR can definitely be useful (whether with or without KNX doesn’t really matter at first).

akanezumi schrieb:

I don’t understand how having a KNX installation affects the decision whether a room temperature controller (RTC) makes sense in the first place. It’s just another way of controlling it.

I didn’t specifically limit my statement to KNX. I just wanted to differentiate between proper measurement and control technology and the bimetallic thermostats that most people have installed.

With proper measurement and control technology, you can respond more precisely to overheating in individual rooms. For example, due to solar gains, equipment running, and so on. In some cases, predictive control can even be applied.

Logging is also very useful. It allows you to analyze exactly how often the valve in each room was closed. This makes it very easy to optimize the hydraulic balancing.