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

Nevertheless, there is no direct heat exchanger like in a [Kontrollierte-Wohnraumlüftung], it remains an air heater.

from on the go

What do you mean by air heating?

So. We were at the open house of our home builder yesterday and now the chimney is back in the game! Yay

Current plan:

Nibe f750 with SAM-40:

[*]we only need a supply temperature of 26°C because the underfloor heating pipes are laid very close together
[*]the SAM-40 module replaces the ventilation system. No cold air flows in through dampers!
[*]I would like to equip the very small water tank (180L) with a simple instantaneous water heater as an emergency backup solution

a Plewa Classcio stove

[*]it only has 3.8kW output

[*]independent of room air
[*]in my opinion, it makes the most sense with an exhaust air heat pump, since heat is produced in the house that the exhaust air heat pump can use

I know you all expressed concerns. But there were no reasonable arguments among the concerns. Opinions like "Just no exhaust air heat pump, it’s no good" don't count because there is no reasoning. That is on a similar level as: "Just no BVB, FCB is better"

The f750 probably doesn’t work with VBH, because on the one hand they are less well insulated, they don’t install a SAM-40, the heated room volume is too large (our home builder installs them up to a max. of 150sqm living space) and the underfloor heating does not match the heat pump. Or I have already read that VBH combines the f750 with completely normal wall radiators. That cannot work.

Why air heating? Air heating is a heater that blows warm air through the house, right? Or it works by warm air rising and then being distributed through the house via air shafts, correct?
The f750 doesn’t do that at all. It heats via underfloor heating. Or do you mean that the SAM-40 module ensures that preheated air is blown through the house? But ideally you have that in every ventilation system? Otherwise, you again have the problem that cold air comes in from outside, because fresh air has to come in somewhere.

I know you have all expressed concerns. But none of the concerns included reasonable arguments. Opinions like "Just no exhaust air heat pump, it's no good" don't count, as there is no justification. That's on a similar level as: "Just no BVB, FCB is better"

It is not our task, the decision is ultimately yours alone anyway, and in the end no one here cares what you finally decide.

And again for understanding: Whether underfloor heating or not, that is never the argument. It is an EXHAUST AIR heat pump in a semi-well insulated house. Just think about how much energy potential could be contained in the exhaust air, and then whether it makes sense to use such technology in a non-passive house.

If you close your eyes to the arguments, you naturally don't see them. The module heats the air with normal heating hot water and itself requires a somewhat higher temperature compared to your supply temperature. So it is not a heat exchanger as with controlled residential ventilation included. To which outside temperature does your supply of 26 degrees refer? The 750 can provide a maximum of 6 kW output via compressor (i.e. heat pump), but a large part of this (already about 1/3 at zero degrees outside temperature) is needed to bring the incoming air to room temperature, which lowers the actual coefficient of performance and thus the efficiency. If your heat demand is low enough, the Nibe 750 may be sufficient. However, you should know the heat demand for that. The instantaneous water heater is a good choice, because when it is cold, the Nibe has hardly any reserves for hot water unless you have a passive house. From on the go

Just google the consumption. Depending on the source, the F750 has an annual consumption of 3,500 to 12,000 kWh. Electrical energy, mind you, at for example 0.257 here with us. That would be up to 3,000 EUR heating costs per year. With a brine heat pump, you might get 300-500 EUR heating costs. With an air heat pump, 400-700 EUR.

The difference to an air heat pump: The air heat pump can pull much, much, much, much, much more air. You don’t want a 10-15 times air exchange. I once googled: such an air heat pump can pull 7,000 m3. Your exhaust air heat pump may pull about 200 m3 per hour, which already results in a high air exchange depending on the house size.