ᐅ Local heating network or air-to-water heat pump?

Hello everyone,

We are facing the difficult decision of which heating system to install. I hope someone here has faced the same choice and might be able to offer some advice.

Details:

- KfW55 standard house
- Living area: 120m² (1,292 sq ft)
- Basement: 45m² (484 sq ft)
- Storage room/small attic on the upper floor: approx. 20m² (215 sq ft)
- Underfloor heating
- The house will be rented out
- The energy performance certificate states a total heated floor area of 210m² (2,260 sq ft)
- According to the plumbing company, the air-to-water heat pump would achieve an annual performance factor of 4.5
- Local district heating costs about €700 (USD equivalent) basic fee plus €0.095 (USD equivalent) per kWh (5-year contract)

Questions:
1. Has anyone here had positive or negative experiences with local district heating?
2. I initially estimated a total energy requirement of 10,500 kWh (about 50 kWh/m² per year x 210 m²). Is this realistic?
3. Based on calculations, the air-to-water heat pump would result in about 50% of the running costs of district heating. Could this be correct? (Investment costs are roughly the same)
4. Am I correct in understanding that the energy performance certificate assumes the entire house is heated, including the basement and attic, since it uses 210 m² as the basis?
5. Does anyone with a KfW55 house have experience with electricity consumption for an air-to-water heat pump (heating and domestic hot water) that they could share?

I would appreciate any responses.

Since you are building the house for rental purposes, I would focus on a) the lowest initial cost and b) the least amount of stress.

Therefore, a local district heating system would be advisable. Energy consumption would then be the tenant’s responsibility.

Thank you for your response. That crossed my mind as well and would be a reason to consider district heating. However, I would also argue that lower operating costs improve rental appeal, which would be the case with a heat pump. It’s definitely not an easy decision overall.

Where is the house located? In the warm Rhineland or the colder eastern region? What is the heating load?
Are only 120 sqm (1,292 sq ft) being heated? Is there a usable basement?
Were you involved in the construction and do you have pictures of the installed underfloor heating? The supply temperatures should be kept low. Some buildings are only “KfW-something” on paper and are made to look good with the heat pump.

For a genuine KfW55 house, you can also use the “air source heat pump.”

Thank you for your reply. The house is not built yet... construction will start soon... location is near Karlsruhe / in the south... so it’s warm. The basement will probably not be heated... or does it make sense to heat it as well, possibly at a lower temperature?

Fips0001 schrieb:

that the rental potential is better when the additional costs are low

You are building to KfW 55 standard and receive the energy certificate. The tenant will look at this (which is basically the same for heat pumps or district heating). They will also appreciate having a low-maintenance heating system—no chimney sweep, no annual servicing, and so on.