ᐅ Remove oil heating, install gas condensing boiler plus solar?
Created on: 18 Mar 2019 09:21
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Pianist
Good day to all readers!
Recently, as I do every two years, I attended the ISH trade fair in Frankfurt. After such an event, you naturally start feeling interested in new home technology. My oil-fired central heating system (Viessmann Vitola 200) is now 20 years old and runs perfectly; even the chimney sweep is satisfied with the readings. Objectively, there is no reason to replace it yet.
On the other hand, I consider myself a responsible person who likes to contribute to making things better. Last year, I replaced my diesel car with a natural gas vehicle, and I also switched to a genuine green electricity provider. Emotionally, I would definitely like to stop burning oil in the future, as I now regard it as almost unforgivable.
Gas supply is available in my street in a suburban area of Berlin. My roof shape is not ideal for solar thermal systems but also not completely unsuitable. It is a half-hipped roof with a north-south ridge, incorporating four dormers. I estimate that about 12 square meters (130 square feet) of collector area could fit on each side in the central section, but this would need to be examined more closely if I proceed.
The space currently occupied by the oil tank I would rather use for a private sauna and cancel my gym membership. I pay 1,000 EUR per year and rarely go due to lack of suitable time slots. The same applies to my father, so that would be about 2,000 EUR per year saved—enough to cover the cost of a sauna.
There would also be room for a sufficiently sized buffer tank. Another aspect is that my main workrooms are located in the basement, which tends to be too cold in summer. From April to October, I switch the system from heating to hot water only.
Now I am wondering: If I install a gas condensing boiler combined with solar thermal, I would ideally have enough hot water in summer and could warm the basement workrooms a little, while using little to no gas. In winter, my gas consumption would likely be less than my current oil use, since a new system would obviously be more efficient than my 20-year-old one.
The downside is that I have to consume gas as I buy it, and can’t purchase it when prices are low, unlike oil, which I can stockpile for over a year and buy when prices dip. Currently, I use about 3,200 liters (845 gallons) of heating oil annually to heat roughly 300 square meters (3,230 square feet) of living and usable space. That’s already significantly better than the national average.
So here is the big question: Is it sensible to switch now, or not? Will it actually improve my energy and cost balance? I assume I will have to switch within five to ten years anyway.
Thanks for all helpful thoughts!
Matthias
Recently, as I do every two years, I attended the ISH trade fair in Frankfurt. After such an event, you naturally start feeling interested in new home technology. My oil-fired central heating system (Viessmann Vitola 200) is now 20 years old and runs perfectly; even the chimney sweep is satisfied with the readings. Objectively, there is no reason to replace it yet.
On the other hand, I consider myself a responsible person who likes to contribute to making things better. Last year, I replaced my diesel car with a natural gas vehicle, and I also switched to a genuine green electricity provider. Emotionally, I would definitely like to stop burning oil in the future, as I now regard it as almost unforgivable.
Gas supply is available in my street in a suburban area of Berlin. My roof shape is not ideal for solar thermal systems but also not completely unsuitable. It is a half-hipped roof with a north-south ridge, incorporating four dormers. I estimate that about 12 square meters (130 square feet) of collector area could fit on each side in the central section, but this would need to be examined more closely if I proceed.
The space currently occupied by the oil tank I would rather use for a private sauna and cancel my gym membership. I pay 1,000 EUR per year and rarely go due to lack of suitable time slots. The same applies to my father, so that would be about 2,000 EUR per year saved—enough to cover the cost of a sauna.
There would also be room for a sufficiently sized buffer tank. Another aspect is that my main workrooms are located in the basement, which tends to be too cold in summer. From April to October, I switch the system from heating to hot water only.
Now I am wondering: If I install a gas condensing boiler combined with solar thermal, I would ideally have enough hot water in summer and could warm the basement workrooms a little, while using little to no gas. In winter, my gas consumption would likely be less than my current oil use, since a new system would obviously be more efficient than my 20-year-old one.
The downside is that I have to consume gas as I buy it, and can’t purchase it when prices are low, unlike oil, which I can stockpile for over a year and buy when prices dip. Currently, I use about 3,200 liters (845 gallons) of heating oil annually to heat roughly 300 square meters (3,230 square feet) of living and usable space. That’s already significantly better than the national average.
So here is the big question: Is it sensible to switch now, or not? Will it actually improve my energy and cost balance? I assume I will have to switch within five to ten years anyway.
Thanks for all helpful thoughts!
Matthias
Pianist schrieb:
No, no underfloor heating Without underfloor heating, don’t worry about the heat pump. It will be too expensive because the annual performance factor will be significantly too high. Replacing all radiators with oversized low-temperature convectors at 40/30°C (104/86°F) might be possible, but still clearly more expensive than your oil or new gas system.
Fuchur schrieb:
Then you should be aware that the same applies to solar thermal systems Well, that is actually different. Photovoltaics without an expensive battery can only be used effectively if demand and generation match exactly. Hot water, on the other hand, can be stored cheaply and used in the evening or morning hours. Solar thermal systems can be used well to support heating during transitional seasons. On south-facing roofs even on sunny winter days, though of course only to a limited extent.
Heating costs of "0€" only work if you don’t include the 6,000–10,000€ cost for the photovoltaic system.
The solar thermal system on the existing roof for heating support is also well subsidized:
2,000€ base grant + 500€ if a new heating system is purchased at the same time + 10% KfW subsidy + possibly additional municipal or regional bank grants.
boxandroof schrieb:
The future belongs to electricity I see. We still have a well-developed, full, functioning gas network. Soon with an additional NordStream2 pipeline, and the US plans to build LNG terminals financed by European gas customers. This does not suggest that gas supply will run out anytime soon. In terms of price, gas is also more predictable than electricity. Electricity prices tend to vary much more year to year due to political decisions than gas. And in existing buildings without underfloor heating, heat pumps will not achieve reasonable annual performance factors in the next 15 years, and electricity will definitely not get cheaper!
Alternatives from an ecological perspective:
Gas-based fuel cells. These also generate electricity but only a few hundred watts. This means you have a high share of self-generated power usage. They are also heavily subsidized by the KfW bank.
Pellet stoves, which also receive BAFA subsidies, and the space currently needed for oil tanks is then needed for pellets. However, pellets are ecologically questionable, as is much mass-produced fuel (pellets from Hungary = Carpathian primeval forests, or shipped from Canada, for example).
Wood log gasification boilers. These also come with generous subsidies and are much better than traditional fireplaces in terms of combustion and emissions. They are especially worthwhile if you have access to inexpensive wood, but also a good option for normal customers. Local fuel supply is definitely possible.
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Deliverer19 Mar 2019 11:05dertill schrieb:
In terms of price, gas is also more predictable than electricity. The latter tends to change its price much more annually due to political decisions compared to gas.I admit, I haven’t checked this with statistics, but still: WHAT?!
Many thanks in between for the many helpful ideas.
I might actually consider consulting an independent energy consultant. In theory, analyzing the house along with the electricity and heating oil consumption should lead to a clear conclusion. And if that conclusion is that everything should remain as it is for now, that’s fine with me.
I also find fuel cells interesting; I have already produced many videos about them. They could even cover my basic consumption, but one must keep in mind that the stack will eventually need to be replaced.
Matthias
I might actually consider consulting an independent energy consultant. In theory, analyzing the house along with the electricity and heating oil consumption should lead to a clear conclusion. And if that conclusion is that everything should remain as it is for now, that’s fine with me.
I also find fuel cells interesting; I have already produced many videos about them. They could even cover my basic consumption, but one must keep in mind that the stack will eventually need to be replaced.
Matthias
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