ᐅ Gas heating or heat pump – air source (e.g., Mitsubishi) or groundwater source
Created on: 6 Dec 2019 09:58
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ludwig88sta
Hello,
basically, you can never really know for sure until maybe 5–10 years later whether the heating system you finally chose was a good decision. The development of gas and electricity prices definitely plays a major role.
Since we are planning a single-family home with about 180–200 m² (1,940–2,150 sq ft) in Bavaria, the question of the "right" heating system naturally arises. At first, I was even interested in a fuel cell heating system, which produces heat and electricity using gas, but currently I am more focused on either a standard gas heating system or a heat pump. I find the fuel cell heating system still too "new" and untested. Maybe it will be more common in 15–20 years.
- Gas heating with relatively low initial costs, good efficiency, and if gas prices don’t soar, I think it’s the most economical purchase? Also, it doesn’t need a fan outside the house that sounds noisy and somewhat spoils the appearance of the house. Of course, no one knows how environmental policies will treat gas heating in the future. This investment could also backfire.
Alternatively,
- an air-source heat pump. Since we are also planning a photovoltaic system, maybe the operating costs (electricity) can mostly be covered by our own solar power? Obviously in winter, when it’s very cold and the panels don’t produce much electricity, this might not be the case. A friend told me about a Mitsubishi heat pump that only switches on the electric heating element at -15 or -20°C (5°F or -4°F). Until then, you only have electricity costs to maintain the heat pump cycle, right? Does anyone have experience with the Mitsubishi heat pump? At what temperature does your heat pump turn on the electric heater?
- The groundwater heat pump scares me a bit because of the higher upfront and installation costs. Drilling two wells, plus maintenance costs for the wells after a few years, etc. Or do you make that back due to better conditions in winter (no cold air because groundwater temperature is fairly constant), so the higher initial costs pay off in the end?
How did you decide and why?
Thank you very much for your opinions and experience reports.
ludwig88sta
basically, you can never really know for sure until maybe 5–10 years later whether the heating system you finally chose was a good decision. The development of gas and electricity prices definitely plays a major role.
Since we are planning a single-family home with about 180–200 m² (1,940–2,150 sq ft) in Bavaria, the question of the "right" heating system naturally arises. At first, I was even interested in a fuel cell heating system, which produces heat and electricity using gas, but currently I am more focused on either a standard gas heating system or a heat pump. I find the fuel cell heating system still too "new" and untested. Maybe it will be more common in 15–20 years.
- Gas heating with relatively low initial costs, good efficiency, and if gas prices don’t soar, I think it’s the most economical purchase? Also, it doesn’t need a fan outside the house that sounds noisy and somewhat spoils the appearance of the house. Of course, no one knows how environmental policies will treat gas heating in the future. This investment could also backfire.
Alternatively,
- an air-source heat pump. Since we are also planning a photovoltaic system, maybe the operating costs (electricity) can mostly be covered by our own solar power? Obviously in winter, when it’s very cold and the panels don’t produce much electricity, this might not be the case. A friend told me about a Mitsubishi heat pump that only switches on the electric heating element at -15 or -20°C (5°F or -4°F). Until then, you only have electricity costs to maintain the heat pump cycle, right? Does anyone have experience with the Mitsubishi heat pump? At what temperature does your heat pump turn on the electric heater?
- The groundwater heat pump scares me a bit because of the higher upfront and installation costs. Drilling two wells, plus maintenance costs for the wells after a few years, etc. Or do you make that back due to better conditions in winter (no cold air because groundwater temperature is fairly constant), so the higher initial costs pay off in the end?
How did you decide and why?
Thank you very much for your opinions and experience reports.
ludwig88sta
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nordanney6 Dec 2019 15:06Bookstar schrieb:
You think so? That's also the case for my acquaintances who have heat pumps. When I still had my last house with a heat pump (which was a new build a few years ago), we had an average monthly electricity cost of €45 for heating at an indoor temperature of around 21.5–22 degrees Celsius (71–72°F).
So about €500–600 per year for a heated area of 300 m² (3,230 sq ft). And that was back in 2015/2016—with a KfW 70 standard (close to 55).
nordanney schrieb:
When I still had my last house with a heat pump (it was a new build a few years ago), we had average monthly heating electricity costs of 45€ at an indoor temperature of 21.5-22 degrees Celsius (70-72°F).
So about 500-600€ per year for 300 square meters (3,230 square feet) of heated area. And that was in 2015/2016 – back then it was a KfW 70 standard (close to 55). Yes, it also depends a lot on the location. Electricity prices were significantly cheaper back then as well. But if I’m lucky, my heating costs will be around 800 euros per year, which would be acceptable.
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ludwig88sta11 Dec 2019 10:03The question is whether a large, powerful heating system is still necessary in a modern, well-insulated single-family house with a heat recovery ventilation system. That’s why my current favorite option is almost a air source heat pump.
ludwig88sta schrieb:
The question is whether a large, high-capacity heating system is still needed in a modern, well-insulated single-family house with a heat recovery ventilation system. That’s why my current favorite is almost a air-source heat pump? This is determined by a heat load calculation, which specifies how large the heat generator needs to be. For me, an air-source heat pump is not an option because the calculated heat load does not include the energy demand for domestic hot water. In other words, you won’t be able to heat the whole house including hot water just from the waste heat alone—that requires an electric heating element. This can work in passive houses if there are correspondingly low heat losses and solar gains can contribute.
The advantage would, of course, be saving the underfloor or panel heating, but the downside is reheating via warmed air. I would find that uncomfortable; underfloor or panel heating is more pleasant than a fan, to put it bluntly.
But in principle, yes, you can also use a controlled ventilation system with a heating coil and heat domestic hot water with a dedicated heat pump, for example. That might be attractive from an investment perspective. Or you could opt for air conditioning that can also provide heating. This is common in modern holiday homes, for example in Denmark, where previously only electric radiators were installed.
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