Hey everyone,
We are currently planning our small house and are facing the big question of which type of heating system to choose.
Gas heating + domestic hot water
Heat pump (air-to-water)
Geothermal energy
I have researched the different types extensively. It is also clear that the initial investment costs vary.
Which heating system is the most cost-effective in terms of operating expenses?
Here are a few key details:
KfW-55 standard
About 140m² (1,500 sq ft)
Controlled ventilation system
Underfloor heating on ground floor and upper floor
Thank you very much for your advice
We are currently planning our small house and are facing the big question of which type of heating system to choose.
Gas heating + domestic hot water
Heat pump (air-to-water)
Geothermal energy
I have researched the different types extensively. It is also clear that the initial investment costs vary.
Which heating system is the most cost-effective in terms of operating expenses?
Here are a few key details:
KfW-55 standard
About 140m² (1,500 sq ft)
Controlled ventilation system
Underfloor heating on ground floor and upper floor
Thank you very much for your advice
We had a long discussion about whether to choose an air-to-water heat pump or gas. Even geothermal energy was briefly considered. After initially deciding on an air-to-water heat pump, we ultimately went with gas. I have to say, that was absolutely the right decision, and I don’t regret it.
For our 250m² (2,690 sq ft) house, we used about 11-12m³ (388-424 cubic feet) of gas per day when it was -18°C (0°F). That cost around 4€ on the coldest day. By the way, this was before the exterior plaster was applied, just after moving in. Currently, our usage is about half that. I’m sure our neighbors with their air-to-water heat pumps were nervously watching their electric meters during that time—I’ve heard of electricity bills around 150€ per month.
For us, the air-to-water heat pump would never have been cost-effective. Even with a gas connection, the heat pump would have cost us 1,800€ more. Simply put: over the next 15 years, we won’t make that money back with an air-to-water heat pump, which typically has a lifespan of about 6-7 years. Few last longer because the compressor usually fails first, which can cost several thousand euros to repair. Of course, a gas heating system can break down too, but keep in mind: gas heating technology has existed for decades, is very mature, and a brand-new condensing gas boiler costs around 4,000€. The idea that you can’t get KfW55 efficiency standard with gas is nonsense! Just search for Stiebel Eltron’s energy regulation system advisor, and you’ll see that it’s achievable with gas. You just need a bit more insulation or more solar thermal collectors. I’d rather invest money in improved insulation than in technology that will fail sooner or later.
Geothermal would have cost us nearly 10,000€ just for the drilling alone. You’ll never recover that cost. It’s purely for idealists. A great idea, but economically nonsense.
Also, keep in mind: there’s no subsidy for air-to-water heat pumps, only for geothermal systems. Some might argue differently, but that’s incorrect. I spoke with BAFA back then and have written confirmation that subsidies for air-to-water heat pumps (1,500€) are only granted if the system achieves an annual performance factor (COP) of 4.5 or higher. Unfortunately, no air-to-water heat pump on the market reaches that—it’s only possible with geothermal.
One more thing: our chimney sweep only needs to come every three years, so that’s no longer a valid argument against gas heating.
Good luck with your decision—I know how tough it is. I’m glad to have it behind me and to have made what was the right choice for me.
For our 250m² (2,690 sq ft) house, we used about 11-12m³ (388-424 cubic feet) of gas per day when it was -18°C (0°F). That cost around 4€ on the coldest day. By the way, this was before the exterior plaster was applied, just after moving in. Currently, our usage is about half that. I’m sure our neighbors with their air-to-water heat pumps were nervously watching their electric meters during that time—I’ve heard of electricity bills around 150€ per month.
For us, the air-to-water heat pump would never have been cost-effective. Even with a gas connection, the heat pump would have cost us 1,800€ more. Simply put: over the next 15 years, we won’t make that money back with an air-to-water heat pump, which typically has a lifespan of about 6-7 years. Few last longer because the compressor usually fails first, which can cost several thousand euros to repair. Of course, a gas heating system can break down too, but keep in mind: gas heating technology has existed for decades, is very mature, and a brand-new condensing gas boiler costs around 4,000€. The idea that you can’t get KfW55 efficiency standard with gas is nonsense! Just search for Stiebel Eltron’s energy regulation system advisor, and you’ll see that it’s achievable with gas. You just need a bit more insulation or more solar thermal collectors. I’d rather invest money in improved insulation than in technology that will fail sooner or later.
Geothermal would have cost us nearly 10,000€ just for the drilling alone. You’ll never recover that cost. It’s purely for idealists. A great idea, but economically nonsense.
Also, keep in mind: there’s no subsidy for air-to-water heat pumps, only for geothermal systems. Some might argue differently, but that’s incorrect. I spoke with BAFA back then and have written confirmation that subsidies for air-to-water heat pumps (1,500€) are only granted if the system achieves an annual performance factor (COP) of 4.5 or higher. Unfortunately, no air-to-water heat pump on the market reaches that—it’s only possible with geothermal.
One more thing: our chimney sweep only needs to come every three years, so that’s no longer a valid argument against gas heating.
Good luck with your decision—I know how tough it is. I’m glad to have it behind me and to have made what was the right choice for me.
Nafetsm schrieb:
And keep in mind: you don’t receive any subsidies for an air-to-water heat pump, only for geothermal systems. Some might argue otherwise… but that’s incorrect. I called BAFA back then and have written confirmation that a subsidy for an air-to-water heat pump is only granted (€1500) if the heat pump achieves a seasonal performance factor of 4.5 or higher. Unfortunately, no air-to-water heat pump can reach that. Only geothermal systems can achieve this. Unfortunately, that is not correct. We have a funding approval from BAFA for our air-to-water heat pump. At least mathematically, and that is what counts for the subsidy, ours has a seasonal performance factor of 4.5.
ares83 schrieb:
Unfortunately, that is incorrect. We have an approved funding commitment for our air-to-water heat pump from BAFA. So ours has, at least theoretically, and that is what counts for the subsidy, an annual performance factor of 4.5.Okay, that may be true. But for many, it’s not enough. It depends on the unit.
Sascha aus H22 Feb 2017 18:33Climbee schrieb:
As far as I know (although I’m not fully informed yet, since we’re not that far along), you cannot get KfW55 funding (or better) with fossil fuels, only up to KfW70 at most.
This is something to keep in mind.
But, as I said, I’m open to being corrected. That’s not correct. We are building a house to the KfW55 standard using only a gas condensing boiler without solar panels. Instead, we invested more in insulation.
Sascha aus H schrieb:
That’s not correct. We are building a house to KfW55 standard using only a gas condensing boiler without solar. Instead, we have invested more in insulation.Where does the renewable share come from? Biogas? Mechanical ventilation with heat recovery?
Sascha aus H22 Feb 2017 20:47Mechanical ventilation with heat recovery
I should have mentioned that, sorry.
I should have mentioned that, sorry.
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