KfW55 with air/water heat pump and decentralized ventilation system possible

Hello,

we are currently planning our timber frame detached house and actually want to use the KfW subsidy (55, 40 or 40 plus).
From the building envelope side, the KfW standard should be reached without any problems, however we want to install an air-water heat pump and a decentralized ventilation system with heat recovery. (Plus photovoltaic & battery)
The KfW leaflet for energy-efficient building however states the requirements for the system concept as:
“Air-water heat pump with surface heating system for heat transfer, central ventilation system with heat recovery (heat provision rate ≥ 80 %)“

Does anyone know if the combination of air-water heat pump & decentralized ventilation system is basically not eligible for funding by KfW?

Lord

Another question, why should someone install something worse for more money?

The evaluation good/bad is a completely different topic and is already extensively discussed in other forums.

Does anyone know if the combination of air-water heat pump & decentralized ventilation system is fundamentally not eligible for funding by the KfW?

That is possible. For example, you do not necessarily need a heat pump or specifically an air-water heat pump for KfW 55, as it states in your text.

That works. For example, you do not necessarily need a heat pump or specifically an air-to-water heat pump for KfW 55, as stated in your text.

I am well aware that there are different system concepts that are subsidized by KfW.
The information sheet states:
For the system technology, one of the following six system concepts must be implemented. The installation location of the heat generator or the heat transfer station must be within the thermal building envelope, and a central domestic hot water preparation must be present. A domestic hot water circulation is permitted.
- Condensing boiler, solar domestic hot water preparation (standard values according to DIN V 4701-10), central ventilation system with heat recovery (heat supply degree ≥ 80 %)
- District heating with certified primary energy factor fp ≤ 0.7, central ventilation system with heat recovery (heat supply degree ≥ 80 %)
- Central biomass heating system based on wood pellets, wood chips or logs, central exhaust air system
- Brine-water heat pump with surface heating system for heat transfer, central exhaust air system
- Water-water heat pump with surface heating system for heat transfer, central exhaust air system
- Air-water heat pump with surface heating system for heat transfer, central ventilation system with heat recovery (heat supply degree ≥ 80 %)


My question, however, is whether in this specific case, an air-to-water heat pump in connection with a decentralized ventilation system can also be subsidized, or whether one of the six specified concepts must necessarily be implemented.

You have to achieve certain values for insulation and primary energy and on paper. How doesn’t matter. KfW 55 is also possible without a ventilation system, to answer the question.

Especially with KfW 55 it is quite easy to achieve. If you are serious, I would aim for KfW 40, since there is less room for creative accounting. You will save sustainably if you plan the air-water heat pump and heating surfaces well, regardless of whether with or without KfW.

I also stumbled upon the information sheet.