Exhaust air heat pump for heating and domestic hot water experiences

Hello, does anyone have experience with an exhaust air heat pump for heating and domestic hot water? How high are the electricity costs? I was offered a Nibe F370 with underfloor heating for a Kfw70 house with 120sqm. Is the Nibe option recommended?

Hello,

...does anyone have experience with an exhaust air heat pump for heating and domestic hot water? How high are the electricity costs?

The planner should be able to answer that question. Has no consumption forecast been created?

...I was offered a Nibe F370 with underfloor heating for a KfW70 house with 120sqm. Is this option recommended?

Heat pumps “live” from their source. An exhaust air heat pump can only use the energy previously put into the system. Where does that come from? A perpetual motion machine does not exist yet, although sellers of such systems like to suggest it.
In a KfW EH70 house, this will very likely fail. The consumption costs will be relatively high. In a PH, the balance would look somewhat different.
Without exact calculation/dimensioning by a building services planner, reliable predictions cannot be made.

Best regards

An air/water heat pump, which is commonly used in a single-family house, has an air circulation of at least 1,200 m³ per hour. From this amount of air, the necessary amount of heat for a 4-person household for heating and hot water can be generated. This works with mature systems and appropriately well-insulated building envelopes without the use of the heating element.
With a purely exhaust air heat pump, however, a relatively small amount of air of about 250 m³ per hour is available for the heat pump compressor, which is why the use of direct electric reheating is often necessary.
Therefore, one should rather avoid exhaust air heat pumps, otherwise there will be higher operating costs in the long term.
By the way, in noise-polluted residential areas, the combination of an exhaust air heat pump with a decentralized apartment ventilation system is not recommended. The noise is brought into the house through the external wall supply air vents.
Cold drafts in the area of the supply air penetrations are another disadvantage.

Best regards
T.H.

This works with mature systems and correspondingly well-insulated building envelopes without the use of the heating element.

Many things may work, but unfortunately that is not particularly efficient

In well planned systems, the share of the heating element accounts for just about 1% of the annual heating work, so it is completely unproblematic.

Best regards