Which heat pump? Ventilation system / Air-to-water heat pump

Unfortunately, the heat capacity of air is very poor, so it has to suck in a lot of exhaust air. How do you replace this? With fresh, cold air from outside. In order for it not to get cold inside, this air must also be heated with the help of the heating system. For that, you need more exhaust air, etc.

I think controlled residential ventilation systems have an efficiency of 90%.

We have two such systems here in the neighborhood. So far, the consumption figures sound quite interesting, even though the really cold winters have not occurred yet.

I think controlled residential ventilation systems have an efficiency of 90%.

We have 2 such systems in the neighborhood here. So far, the consumption values sound quite interesting, even though the really cold winters have not yet occurred.

I think you are talking about something different than I am. An exhaust air heat pump is something different than a controlled residential ventilation system.
Once the exhaust air heat pump has extracted the heat from the air, there is not much left for heat exchange.

Don’t they advertise that both are linked there? Besides, the CoP of 2 is quite low, right?

But not like with a controlled ventilation system. In the case of an exhaust air heat pump, the fresh air comes in through outside air vents, so it comes in cold there or very hot in summer.

Don't they advertise that both are coupled there? Besides, the COP of 2 is quite low, isn't it?

Not as coupled as with a controlled residential ventilation system, that can't work. The higher the COP, the worse the concept is, imagine the COP being 5, then the exhaust air pump would have to extract 4.8 kW of heat from the air instead of 3 kW with 6 kW heat output for the house. That would mean a huge amount more air would have to be moved through (and much more incoming cold air).

But not like with a controlled residential ventilation system. With an exhaust air heat pump, the fresh air comes in through outdoor air vents, so it comes in cold there or very hot in summer.

She has already written several times that they were offered it with a supply air module. There, supply and exhaust air are installed centrally. The supply air can also be preheated. So not several vents in the rooms.

Regarding the water tank: 180l is the hot water. Cold water is added to that as well.