SoL
2022-02-13 14:20:44
- #1
Hello everyone,
I need your assessment regarding the heating choice. We (2 adults, 4 children) are currently in talks with a general contractor for a house, which sounds quite good so far, the construction service description is okay. We are not planning to reach a specific KFW standard but will end up somewhere between 70 and 55. The heating load calculation is, of course, not finished yet as the contract is unsigned.
The standard offering from the general contractor includes:
Gas heating: Vaillant auroCOMPACT VSC S 206/4-5 190 condensing compact unit
Rated at 20 kW (wow, why?)
Includes a 190L hot water storage tank, packaged with 2.5m² solar thermal system
Alternatively, he offers an air-water heat pump credited against the gas heating and solar thermal:
Thermia iTec Plus with 9 kW capacity, cooling function, and 300L hot water storage next to it.
Actually, I would prefer going towards the heat pump, but:
The surcharge for the heat pump solution is a hefty €8,100. That way, we wouldn’t need a gas connection...
Maybe I’m mistaken or it doesn’t add up to go for the heat pump?
Even if one achieves a COP of 3.5 or 4 with it, the extra costs of €8,100 minus €2,500 for the gas connection = €5,600 will only pay off very, very late.
At €0.30 per kWh electricity, with 10,000 kWh annual consumption and a COP of 4, we would have costs of €750. At a gas price of €0.10, costs would be €1,000. Difference thus €250/year, the extra costs amortize (disregarding the solar thermal) only after 22 years.
Is that correct, or do I have a screw loose / error in the calculation? I tend towards gas with this extra cost, possibly with an additional hot water storage tank.
Thanks and best regards
SoL
I need your assessment regarding the heating choice. We (2 adults, 4 children) are currently in talks with a general contractor for a house, which sounds quite good so far, the construction service description is okay. We are not planning to reach a specific KFW standard but will end up somewhere between 70 and 55. The heating load calculation is, of course, not finished yet as the contract is unsigned.
The standard offering from the general contractor includes:
Gas heating: Vaillant auroCOMPACT VSC S 206/4-5 190 condensing compact unit
Rated at 20 kW (wow, why?)
Includes a 190L hot water storage tank, packaged with 2.5m² solar thermal system
Alternatively, he offers an air-water heat pump credited against the gas heating and solar thermal:
Thermia iTec Plus with 9 kW capacity, cooling function, and 300L hot water storage next to it.
Actually, I would prefer going towards the heat pump, but:
The surcharge for the heat pump solution is a hefty €8,100. That way, we wouldn’t need a gas connection...
Maybe I’m mistaken or it doesn’t add up to go for the heat pump?
Even if one achieves a COP of 3.5 or 4 with it, the extra costs of €8,100 minus €2,500 for the gas connection = €5,600 will only pay off very, very late.
At €0.30 per kWh electricity, with 10,000 kWh annual consumption and a COP of 4, we would have costs of €750. At a gas price of €0.10, costs would be €1,000. Difference thus €250/year, the extra costs amortize (disregarding the solar thermal) only after 22 years.
Is that correct, or do I have a screw loose / error in the calculation? I tend towards gas with this extra cost, possibly with an additional hot water storage tank.
Thanks and best regards
SoL