Low humidity room climate (25%)

Since every person has their own preferences here, it is not necessarily the case. But globally speaking, yes, from a certain outdoor temperature onwards it becomes very dry inside.

Unfortunately, yes. And my condolences for this uncomfortable heating system from my side as well. There are two causes for the dry air with this type of heating system:

1. The installed cross-counterflow heat exchanger only recovers heat from the exhaust air. The humidity in the exhaust air is completely transported outside. Since the absolute humidity of the supply air is much lower in cold outdoor air, the relative humidity inside drops to a very unpleasant level. As a remedy, one can retrofit an enthalpy or rotary heat exchanger instead of the cross heat exchanger. This also recovers the humidity from the exhaust air. This would increase the indoor humidity. Unfortunately, the system manufacturer must offer such a heat exchanger.

2. The second cause is the required high volume flow to cover the heating demand, since the heat capacity of air is low. That means the colder it is outside, the lower the humidity of the supply air, which worsens the already higher required volume flows in cold conditions. To reduce the problem, the required volume flow must be reduced. To do this, one can:
- reduce the heating load by improving the insulation of the house (for example, the top floor ceiling) or lower the indoor temperatures
- partly cover the heating load with an additional heater, e.g., split air conditioning, which keeps the humidity indoors so the primary heating system supplies less outdoor air
- increase the supply air temperature. This reduces the amount of supply air needed to cover the heating load and thus dries the house less. Unfortunately, this has the disadvantage that the already poor efficiency of the heating system decreases further.

Fixing the above causes will reduce the problem but not completely solve it. IMHO, the ultimate solution is a humidification coil in the heating supply air. That costs a bit of money. But then dry air should be a thing of the past. Google for example Hygrobox Helios or simply air humidifier ventilation. A pleasant climate should be worth €5,000 to you. Maybe the home builder will consider a goodwill contribution to solve the problem. After all, they sold you this uncomfortable heating system without properly informing you about it.

Regards, Nika

Comfort climate heating. One should probably show this to a lawyer to see if there is a defect here. At 25% rH, there can hardly be any talk of comfort anymore. I would certainly laugh heartily if this marketing crap ever had consequences. All this talk of climate walls, etc., is barely bearable anymore.

IMHO the ultimate solution is a humidification coil in the heating supply air

Something like that is great but has a very high power consumption, which must be taken into account.

Just checked, we have 26.3 degrees in the dining room with a humidity of 31%.

Thanks to the enthalpy exchanger in the ventilation, the values are already pretty good. We are very satisfied.

Something like that is great but has a very high power consumption, you have to take that into account.

Well, sometimes you have to fight fire with fire ops:

26° wow... We also often had it too warm at the beginning when we first had to adjust the heating. What never bothered me at home, but then I was freezing everywhere else, which was not so nice. By now, I think we have about 22° in the living room.