First of all, hi everyone
We are planning to build a new house, specifically a KfW 70 standard home from Massa Haus with 160m² (1722 sq ft) of living space.
I’m still completely undecided about which heating system to choose.
There are no gas lines available, so we would need to rent a gas tank.
The standard package includes a gas boiler with a 300L (79 gallons) storage tank and about 5m² (54 sq ft) of flat-plate solar collectors.
A controlled ventilation system with heat recovery is always included.
For now, we have decided on an air source heat pump with underfloor heating (around €13,000). Since it is a compact system, the storage tank will probably be smaller. For an additional €1,500, we could add two high-performance evacuated tube solar collectors on the roof (about €14,500 extra compared to the standard package).
If we calculate differently and stick with the gas boiler, we would also have underfloor heating with a 750L (198 gallons) storage tank (160L domestic hot water and 590L buffer) for hot water and heating support, plus about 10m² (108 sq ft) of solar collectors (approximately €16,500 extra).
One advantage I’ve read about is that the heat pump has much lower maintenance costs (inspections, chimney maintenance, etc.).
I am really unsure about what to decide.
If we go with the heat pump, should we add the solar water collectors and save money, or is it better to invest more and install photovoltaic panels on the roof? (If you can even get anything useful for around €3,500.)
We are planning to build a new house, specifically a KfW 70 standard home from Massa Haus with 160m² (1722 sq ft) of living space.
I’m still completely undecided about which heating system to choose.
There are no gas lines available, so we would need to rent a gas tank.
The standard package includes a gas boiler with a 300L (79 gallons) storage tank and about 5m² (54 sq ft) of flat-plate solar collectors.
A controlled ventilation system with heat recovery is always included.
For now, we have decided on an air source heat pump with underfloor heating (around €13,000). Since it is a compact system, the storage tank will probably be smaller. For an additional €1,500, we could add two high-performance evacuated tube solar collectors on the roof (about €14,500 extra compared to the standard package).
If we calculate differently and stick with the gas boiler, we would also have underfloor heating with a 750L (198 gallons) storage tank (160L domestic hot water and 590L buffer) for hot water and heating support, plus about 10m² (108 sq ft) of solar collectors (approximately €16,500 extra).
One advantage I’ve read about is that the heat pump has much lower maintenance costs (inspections, chimney maintenance, etc.).
I am really unsure about what to decide.
If we go with the heat pump, should we add the solar water collectors and save money, or is it better to invest more and install photovoltaic panels on the roof? (If you can even get anything useful for around €3,500.)
Hello, I fully agree with Erik_IEU’s post. There isn’t much more to add:
A KfW 70 prefabricated wooden house, highly insulated (standard in timber prefabrication), combined with a gas condensing boiler and solar system is the typical standard solution and energetically sufficient. Anything extra you add or layer on will improve the energy balance but will also increase costs. The weak point in the energy performance of a prefabricated wooden house, with good German manufacturers, is never the house itself but the foundation slab or the basement. However, all manufacturers offer solutions for this as well.
Best regards, CADAMaRa
A KfW 70 prefabricated wooden house, highly insulated (standard in timber prefabrication), combined with a gas condensing boiler and solar system is the typical standard solution and energetically sufficient. Anything extra you add or layer on will improve the energy balance but will also increase costs. The weak point in the energy performance of a prefabricated wooden house, with good German manufacturers, is never the house itself but the foundation slab or the basement. However, all manufacturers offer solutions for this as well.
Best regards, CADAMaRa
B
Bauexperte13 Dec 2011 12:31Hello,
In my opinion, you should reconsider this statement carefully.
Kind regards
Erik_IEU schrieb:
With a solar thermal system that ... and supports the heating, there is an opportunity to make an environmental contribution ...
In my opinion, you should reconsider this statement carefully.
Kind regards
That definitely helps me a bit already.
What we definitely want is underfloor heating; it also reduces energy consumption somewhat, or am I mistaken about that?
The problem with gas is that I still need a tank, which is not the case with a heat pump.
On the other hand, I have often been advised against compact heat pump units, but the alternatives are very expensive.
And if I calculate that I need to take in about 18,000 kWh more, that’s about 65 USD per month, and you can’t really save that much, even with the best technology, right?
What we definitely want is underfloor heating; it also reduces energy consumption somewhat, or am I mistaken about that?
The problem with gas is that I still need a tank, which is not the case with a heat pump.
On the other hand, I have often been advised against compact heat pump units, but the alternatives are very expensive.
And if I calculate that I need to take in about 18,000 kWh more, that’s about 65 USD per month, and you can’t really save that much, even with the best technology, right?
Underfloor heating is essential for energy-efficient heating. Because of the low system temperature required by underfloor heating, a gas condensing boiler also operates more efficiently. The low return temperature allows the condensing effect to be fully utilized.
Regarding the gas supply, I would definitely recommend contacting the energy provider. The coverage areas of energy companies are gradually expanding. If it becomes clear that a supply will be available in the near future, a tank would only be a temporary solution that can be rented for that period.
Regarding the gas supply, I would definitely recommend contacting the energy provider. The coverage areas of energy companies are gradually expanding. If it becomes clear that a supply will be available in the near future, a tank would only be a temporary solution that can be rented for that period.
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Bauexperte10 Jan 2012 20:40Hello,
Hmm... isn’t it rather the case that gas suppliers are increasingly left with unused pipelines (infrastructure) and therefore often try to establish a gas connection as a "must"?
Kind regards
Erik_IEU schrieb:
... The supply areas of the energy companies are gradually being expanded.
Hmm... isn’t it rather the case that gas suppliers are increasingly left with unused pipelines (infrastructure) and therefore often try to establish a gas connection as a "must"?
Kind regards
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