Air-water heat pump or gas + controlled residential ventilation in a 135 sqm single-family house?

Thank you for your answers!

We will have the property soon and will then build with a local developer.

The controlled residential ventilation would be too expensive for me if I were to buy it in addition to the air-water heat pump.
But if I could save some money now with a gas boiler, controlled residential ventilation might be possible again.

So we would really like to have controlled residential ventilation, my wife has some problems with pollen...

Take it, and everyone will be happy about the comfort. For me, there is nothing to consider, especially because of the allergy.

The price of your controlled residential ventilation already points in that direction, but I would place value on a central controlled residential ventilation system. In terms of energy costs, the thing obviously doesn’t pay off, as has already written. Here just as an addition, not to give the impression from the sentence that controlled residential ventilation systems are energy guzzlers. Rotary heat exchangers inherently consume somewhat more than plate heat exchanger systems because the rotor must continuously, albeit slowly, rotate in addition to the fans responsible for the air volume flow. In the Zehnder ComfoAir Q350, which seems popular in my impression, the power consumption at level 4 (of 8) is specified as 44W, which should correspond to the volume flow of normal ventilation, provided the device was correctly configured. The energy expenditure is therefore limited. The K in controlled residential ventilation primarily stands for me for comfort, and for that, I gladly leave a weak light bulb burning all day in a figurative sense, since that is about how much the controlled residential ventilation system comparatively consumes. For the fact that I always have fresh, filtered air (pollen), a good investment for me.

So I have to say that every euro spent on the controlled residential ventilation system was worth it.

Please roughly compare your consumption (gas/electricity) at Check24. And calculate against each other whether and when something pays off. Taking into account that a gas connection also has to be installed in the house.

Finally got confirmation today! It is possible to do without solar and will therefore only take gas + [Kontrollierte-Wohnraumlüftung]!

Finally got the confirmation today! It is possible to do without solar and we will therefore only take gas + controlled residential ventilation!

Since I have also dealt with the problem, I would be interested to know exactly what and above all from whom you received this confirmation?

I had dealt a bit with the topic and came to the conclusion that this no longer works so easily because of the Renewable Energy Heat Act in connection with the Energy Saving Ordinance 2016?

As a replacement measure for (e.g.) use of solar radiation with a 15% share of the heating and cooling energy demand, only the following would be possible:

1. Residential ventilation with heat recovery from exhaust air, whereby this must save/cover at least 50% of the total (!) heat demand of the house
( § 7 paragraph 1 no. 1 a) Renewable Energy Heat Act)

2. 15% better insulation than Energy Saving Ordinance 2016 and 15% lower annual primary energy demand
( § 7 paragraph 1 no. 2 in conjunction with
VII no. 1 of the annex to the Renewable Energy Heat Act)

Or are you building a KfW55 house?

Does a KfW55 house automatically have a 15% lower annual primary energy demand and 15% better insulation than the Energy Saving Ordinance?

Does having a KfW55 house automatically mean a 15% lower annual primary energy demand and 15% better insulation than the Energy Saving Ordinance?

Qp 55% (energy demand) H't 70% ("insulation")

This is calculated by the energy consultant who prepares the thermal protection certificate or the KFW certificates, provided a KFW program is used.