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.
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.
D
Deliverer1 Jun 2021 14:00Since everything is enclosed within an insulated envelope, all areas need to be heated. Otherwise, the ground floor will warm the basement, making it either too cold or requiring (inefficient) additional heating output for the ground floor. A temperature difference of about two degrees is reasonable. More than that doesn’t make sense.
With this size and KFW55 standard in the south, annual costs with a heat pump are lower than the basic fee for district heating.
So for me, the choice is clear...
Edit: In this case, I would also install photovoltaic panels on the roof and rent it out with heating included. Remove individual room controls to prevent tenants from misusing the system.
With this size and KFW55 standard in the south, annual costs with a heat pump are lower than the basic fee for district heating.
So for me, the choice is clear...
Edit: In this case, I would also install photovoltaic panels on the roof and rent it out with heating included. Remove individual room controls to prevent tenants from misusing the system.
N
nordanney1 Jun 2021 14:22Deliverer schrieb:
Edit: In this case, I would also install photovoltaic panels on the roof and rent it out with heating included.No tenant electricity scheme as well! That’s complicated. Deliverer schrieb:
Remove the individual room control so the tenant doesn’t mess around.They will directly adjust the flow rates. Guaranteed 100%. I can say that from rental experience.D
Deliverer1 Jun 2021 14:28nordanney schrieb:
Not tenant electricity as well! That’s complicated.
It directly affects the flow rates. 100% guaranteed. I can say that from rental experience. Yes – tenant electricity isn’t exactly simple. But first of all, the federal government has been required to eliminate the bureaucracy around it for six months now. So sooner or later something will have to change. Alternatively, just route the electricity through the heat pump meter, so it remains your electricity. Then you’re only selling “a warm house.”
And regarding the flow rates, you need a reliable tenant or you just lock the distribution boxes. In some buildings, the heating rooms are also locked...
N
nordanney1 Jun 2021 14:40Deliverer schrieb:
And because of the flow rates, you need a responsible tenant, or you just lock the distribution boxes.... and risk a rent reduction because the heating cannot be adjusted. It is mandatory that the tenant can control the heating.Sure, you can do all that. But it would be too complicated for me. The tenant can just use the low-maintenance district heating.
Thank you all, photovoltaics are out of the question anyway... but I think the trend is moving towards heat pumps... my gut feeling has been telling me that all along. As a landlord, I could say it doesn’t matter since the costs are borne by the tenant... but reading other forums, sometimes the expenses are as high as for an older building... and since you commit to at least 5 years, it gets complicated.
One more question: for KfW55 standard and this size, is 10,500 kWh for heating and hot water realistic?
Thanks everyone!
One more question: for KfW55 standard and this size, is 10,500 kWh for heating and hot water realistic?
Thanks everyone!
D
Deliverer1 Jun 2021 15:29Fips0001 schrieb:
Photovoltaics are out of the question anyway....Why? Do you already have too much money?Similar topics