Central controlled residential ventilation with heat recovery: Are rooms individually controllable?

There are already central controlled residential ventilation systems with multi-zone regulation, where in summer, for example, the bedroom ventilation is brought into the house via a bypass so that it is not further heated.

Isn't it normal that in summer the air is not further heated, but there is "only" ventilation?

Yes and no, it should be normal, but there are still some systems that don't have a bypass... we have one in the rental place :/

Isn't it normal that in summer the air is not heated further, but there is "only" ventilation?

The heat pump of course does not run then, but ideally you also avoid heat recovery.

First of all, thank you very much for your feedback!

How "cold" does your bedroom need to be? Since the whole house is ventilated and you also have air exchange through the doors (or frames, depending on your preference), the temperature will always equalize throughout the house again and again.

Ideally 18°C, which of course is not achievable in summer. As cool as possible. But in summer I want to cool the whole house at night anyway, so the problem lies rather in winter. Of course, heat is also transferred through briefly open doors, walls, etc., but I don't want to worsen the problem by active compensating ventilation.

Constant flow system is the magic word - then controllers in front of the rooms.

Hmm, I can't find any real definition of a constant volume flow controller anywhere. If it does what the name says, then it's rather the opposite of what I want. The volume flow should adjust dynamically and not be kept constant.

There are already central controlled residential ventilation systems with multi-zone regulation, where in summer, for example, the bedroom ventilation is brought into the house via a bypass so that it is not further heated.

Ah ok. Thanks for the tip, I will look into that.

In general, you are right - a huge effort is made to achieve a state that is quite similar to a conventional house without central controlled residential ventilation. I will continue to think about it...

So I can tell you from my experience... what you are planning is relatively pointless... air is a poor medium and with a [Kontrollierte-Wohnraumlüftung] neither acceptable cooling nor heating results can be achieved without additional cooling or heating...

That is why you won’t find anything on the topic, because it simply doesn’t make sense...

And as Lex already wrote, the bypass is only of little help...

A [Kontrollierte-Wohnraumlüftung] is neither an air conditioning system nor a heater... it only provides fresh air and the temperature differences at the valve are negligible when the underfloor heating is running and the sun shines into the room during the day...

With a controlled residential ventilation system, neither acceptable cooling nor heating results can be achieved without additional cooling or heating...
...
A controlled residential ventilation system is neither an air conditioner nor a heater... it only provides fresh air and the temperature differences at the valve are negligible when the underfloor heating is running and the sun is shining into the room during the day...

I have tried to roughly estimate this.

Assumptions:

[*]In a room at T1=18°C, air at temperature T2=21.5°C is blown in (while air at temperature T1 escapes through slots in the door).

[*]Two people are sleeping in the room; a recommended airflow is about I = 50 m³/h = 50/3600 m³/s.

[*]The density of air is rho = 1.293 kg/m³.

[*]The specific heat capacity of air (at constant pressure) is cp = 1005 J/(kg K).

[*]The heat power brought into the room through air exchange is A = cp * I * rho * (T2-T1) = 63 J/s = 63 W. (Compare the first formula in the Wikipedia article on specific heat and note that 1 joule = 1 watt-second.) (This, of course, only applies as long as the room temperature is 18°C. The power is proportional to the difference T2-T1 and thus decreases as the room warms up.)

I estimate the heat output of a sleeping adult at about 40W to 80W (ask Google), so quite comparable to the heat output of the ventilation.

The ventilation system is therefore a poor heater if you compare it to a radiator. But it is a good power output compared to a human and thus quite relevant!