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.
Joedreck schrieb:
175 liters (46 gallons) are heated very quickly by the solar thermal system, causing the system to stagnate. Otherwise, the water in the storage tank would start to boil and escape.
This causes the fluid in the solar thermal system to boil, which is bad. Are we talking about the same thing? I previously searched online about a hot water storage tank and which size we need. The sources agreed that 175 liters (46 gallons) is more than enough. Now you're saying that it’s not enough because the water boils? Or are we not talking about the hot water storage tank?
You are both talking about hot water storage. @Joedreck refers to (gas boiler +) solar thermal system, while you probably refer to an air-to-water heat pump (possibly combined with photovoltaic – but that is independent of this). Joedreck explains in the post you quoted why the hot water storage tank needs to be sized sufficiently large when using solar thermal systems.
This is irrelevant if solar thermal is not used.
This is irrelevant if solar thermal is not used.
Tolentino schrieb:
You are both talking about a hot water storage tank. @Joedreck refers to (gas boiler +) solar thermal system, while you are probably referring to an air-to-water heat pump (possibly with photovoltaic panels – but that is independent of this). Joedreck explains in the post you quoted why the hot water storage tank for solar thermal needs to be properly sized.
This is irrelevant if solar thermal is not used. Ok. Understood, thanks.
For an air-to-water heat pump in a KfW55 house, 175 liters (46 gallons) is far too small. We have a 300-liter (79 gallons) tank for 2 adults and 2 children – that usually isn’t enough for 24 hours. With gas, it wouldn’t matter because it just reheats continuously. With an air-to-water heat pump, especially if you also have photovoltaics, you want to make use of midday heat and sunshine. Besides, a heat pump doesn’t recharge the storage tank quickly in 15 minutes.
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