ᐅ New Single-Family Home Built to KfW55 Standard – Which Heating System to Choose?
Created on: 19 Jul 2020 12:19
T
Traube348
Hello everyone,
I have read many articles and would now like to benefit from the extensive knowledge of the members here.
A brief overview of my building project:
- Single-family house with approximately 160sqm (1,722 sq ft) of living space
- No basement, 2 full floors with an unfinished attic
- Relatively large window areas and an open-plan design with a staircase in the living area
- Underfloor heating throughout the house with tile flooring
- KfW 55 standard with timber frame construction
- A wood-burning stove will be installed
Unfortunately, I have little experience in this area and rely on recommendations from others regarding heating.
On the ground floor, we have a utility room of 8sqm (86 sq ft) where we would like to accommodate all the technical equipment.
The builder recommends installing a central ventilation system, which we would like to do.
Now to my question:
There is a gas connection in our building area, and a friend told me we should definitely heat with a gas boiler. To meet the KfW standard, according to the energy consultant, we still need to install 9sqm (97 sq ft) of solar panels on the roof.
A heating engineer friend advises: choose an air-to-water heat pump – split system Weishaupt LS 8-BREK – so you can avoid the solar requirement.
I have requested quotes for both options from different heating engineers, and they come out roughly the same in price.
Since I have heard many statements opposing air-to-water heat pumps, I tend to prefer gas.
However, the main challenge is the limited space in the utility room. In addition to the heating system, the two-flue fireplace, and the ventilation system, the electrical control cabinet as well as the washing machine and dryer are also planned to be located there.
Is there anyone who has faced a similar space issue?
What would you recommend?
Thank you very much in advance for your help.
I have read many articles and would now like to benefit from the extensive knowledge of the members here.
A brief overview of my building project:
- Single-family house with approximately 160sqm (1,722 sq ft) of living space
- No basement, 2 full floors with an unfinished attic
- Relatively large window areas and an open-plan design with a staircase in the living area
- Underfloor heating throughout the house with tile flooring
- KfW 55 standard with timber frame construction
- A wood-burning stove will be installed
Unfortunately, I have little experience in this area and rely on recommendations from others regarding heating.
On the ground floor, we have a utility room of 8sqm (86 sq ft) where we would like to accommodate all the technical equipment.
The builder recommends installing a central ventilation system, which we would like to do.
Now to my question:
There is a gas connection in our building area, and a friend told me we should definitely heat with a gas boiler. To meet the KfW standard, according to the energy consultant, we still need to install 9sqm (97 sq ft) of solar panels on the roof.
A heating engineer friend advises: choose an air-to-water heat pump – split system Weishaupt LS 8-BREK – so you can avoid the solar requirement.
I have requested quotes for both options from different heating engineers, and they come out roughly the same in price.
Since I have heard many statements opposing air-to-water heat pumps, I tend to prefer gas.
However, the main challenge is the limited space in the utility room. In addition to the heating system, the two-flue fireplace, and the ventilation system, the electrical control cabinet as well as the washing machine and dryer are also planned to be located there.
Is there anyone who has faced a similar space issue?
What would you recommend?
Thank you very much in advance for your help.
nordanney schrieb:
Then your heating system design is simply bad. Sorry for the blunt words.
The energy consumption is a total disaster.
I currently have similar costs per square meter in my 1960s apartment with standard radiators. You are welcome to share your subjective opinion; I have no problem with that. For 210m² (2261 sq ft) of heated area including the basement, according to forums, acquaintances, and heat pump databases, this is not a poor value. Where the disaster is supposed to be remains a mystery to me.
A ground source heat pump only pays off after about 25 years. That’s why they are so rare in new housing developments.
D
Daniel-Sp23 Jul 2020 14:26Mycraft schrieb:
If at all possible and properly planned and executed, it is definitely preferable to an air-to-water or air-to-air heat pump. The question was whether it is cost-effective.
You can estimate that. Calculate the additional investment minus higher subsidies. Then calculate how much more electricity the air-to-water heat pump will consume compared to the ground-to-water heat pump. Then you will know after how many years you will have recovered the additional investment.
You could save more with the ground-to-water heat pump option if, instead of installing boreholes yourself, you install a horizontal loop collector.
Ybias78 schrieb:
In our quote, instead of an air-to-water heat pump, we have a ground-to-water heat pump. It costs about €7,500. Does anyone have experience with a ground-to-water heat pump? The plan is to drill twice to a depth of 90m (295 feet). The question is whether the extra cost is worth it? As a beginner, it seems logical to me that you can transfer heat better from the ground than from the air, especially during the winter months.It doesn’t pay off. Taking our house as an example—built to KfW 55 standard with an air-to-water heat pump—I could save about 400 kWh of electricity per year with a well-functioning ground-to-water heat pump. Considering our current photovoltaic system, that equals approximately €80-100 annually, meaning 70-100 years to break even (without interest or subsidies).Lumpi_LE schrieb:
It doesn't pay off. If I take our house, kfw55 standard with an air-to-water heat pump, I could save about 400 kWh of electricity per year with a well-functioning ground-source heat pump—currently that's about €80–100 per year considering photovoltaics, so it would take roughly 70–100 years to break even (calculated without interest or subsidies).Thanks. Now the question about the air-to-water heat pump. Is it better to have an outdoor "fan" unit, or can it also be installed indoors in the utility room? And is the unit inside the house noisy?
D
Daniel-Sp23 Jul 2020 14:41Ybias78 schrieb:
Thanks. Then a question about air-to-water heat pumps. Is it better to have an outdoor “fan” unit, or can it also be installed inside the utility room? And is the unit inside the house noisy?Placement is flexible, just not in the living room. I have one installed indoors. The utility room is located directly next to the living room, with a child’s bedroom right above. We don’t hear it in our timber frame house (you can only hear it inside the utility room). The range of units for indoor installation is smaller, including options for different capacity classes.
Always keep in mind that sound is unpredictable and difficult to estimate. If you are sensitive to it, you should definitely avoid placing equipment indoors. It might work out fine, as in Daniel’s case, but what will you do if you experience a constant hum or similar noise inside the house? Then it can become very costly...
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