ᐅ What to replace an oil heating system from 1989 in an old, characterful house with?
Created on: 9 Jan 2021 14:19
M
meowmeow
Hello dear forum,
we have an old timber-framed house in the Alpine foreland. Built around 1910 with an extension from the 1960s, the original building has a basement, the extension does not. The insulation is rather poor, and the windows are either double-glazed or old. A hailstorm completely destroyed our roof, so a new roof with good insulation has now been installed.
Currently, we have a Viessmann oil heating system from 1989 with a 2000l (528 gallons) oil tank in the basement, which has caused no major problems so far. The hot water is also centrally supplied by this system. With the old roof, we used about 1900-2500l (502-660 gallons) of oil in winter, depending on the season. With the new roof, we don’t have experience yet, but I expect some improvement. The house has about 115m2 (1238 square feet) of living space, heated by radiators.
Since the heating system is getting old and there are currently larger subsidy programs, we are considering modernization. From my research so far, a heat pump seems to be out of the question because we would need a better-insulated house and underfloor heating? Other types of electric heating seem even less economical?
The least invasive option would probably be a new condensing oil boiler, but these are not subsidized, so I could just wait until the old one breaks down?
A pellet heating system seems too complicated to operate? My mother will soon be 70 and often lives alone in the house. In her old age, I don’t want to put too much strain on her. We frequently visit with our child for several days, but mostly in summer. Also, the long transition phase with low heating loads appears to speak against a pellet system.
I can’t really estimate the costs for gas. A gas connection might be possible with the local supplier if the neighbors join in. We would need about 60-70m (197-230 feet) of gas pipeline on our own property. What costs should I roughly expect? Alternatively, a tank could be buried in the garden, but we are not very enthusiastic about that idea. We are somewhat confused by current politics: on the one hand, fossil fuels are supposed to become much more expensive to promote renewable energy, but on the other hand, gas condensing boilers are heavily subsidized?
For sentimental reasons, we could imagine installing a water-bearing wood stove in the living room. We already have a wood-burning stove in the kitchen where we occasionally cook, and which also provides some heating in winter.
However, it would have to connect to the same chimney currently used by the oil heating system – or the future gas heating system – and from what I understand, this is not allowed, so I might have to give up that dream, right?
We are considering a photovoltaic system on the roof, but we plan to remove the attic floor and renovate the upstairs room within about 5-10 years to get higher ceilings. This would also include adding a few skylights. I should probably wait for these renovation measures first.
What would you recommend? How should the new heating system be sized – I assume this can be calculated quite well based on previous energy consumption?
Thank you very much for your time and help!
we have an old timber-framed house in the Alpine foreland. Built around 1910 with an extension from the 1960s, the original building has a basement, the extension does not. The insulation is rather poor, and the windows are either double-glazed or old. A hailstorm completely destroyed our roof, so a new roof with good insulation has now been installed.
Currently, we have a Viessmann oil heating system from 1989 with a 2000l (528 gallons) oil tank in the basement, which has caused no major problems so far. The hot water is also centrally supplied by this system. With the old roof, we used about 1900-2500l (502-660 gallons) of oil in winter, depending on the season. With the new roof, we don’t have experience yet, but I expect some improvement. The house has about 115m2 (1238 square feet) of living space, heated by radiators.
Since the heating system is getting old and there are currently larger subsidy programs, we are considering modernization. From my research so far, a heat pump seems to be out of the question because we would need a better-insulated house and underfloor heating? Other types of electric heating seem even less economical?
The least invasive option would probably be a new condensing oil boiler, but these are not subsidized, so I could just wait until the old one breaks down?
A pellet heating system seems too complicated to operate? My mother will soon be 70 and often lives alone in the house. In her old age, I don’t want to put too much strain on her. We frequently visit with our child for several days, but mostly in summer. Also, the long transition phase with low heating loads appears to speak against a pellet system.
I can’t really estimate the costs for gas. A gas connection might be possible with the local supplier if the neighbors join in. We would need about 60-70m (197-230 feet) of gas pipeline on our own property. What costs should I roughly expect? Alternatively, a tank could be buried in the garden, but we are not very enthusiastic about that idea. We are somewhat confused by current politics: on the one hand, fossil fuels are supposed to become much more expensive to promote renewable energy, but on the other hand, gas condensing boilers are heavily subsidized?
For sentimental reasons, we could imagine installing a water-bearing wood stove in the living room. We already have a wood-burning stove in the kitchen where we occasionally cook, and which also provides some heating in winter.
However, it would have to connect to the same chimney currently used by the oil heating system – or the future gas heating system – and from what I understand, this is not allowed, so I might have to give up that dream, right?
We are considering a photovoltaic system on the roof, but we plan to remove the attic floor and renovate the upstairs room within about 5-10 years to get higher ceilings. This would also include adding a few skylights. I should probably wait for these renovation measures first.
What would you recommend? How should the new heating system be sized – I assume this can be calculated quite well based on previous energy consumption?
Thank you very much for your time and help!
Hmm, I think 700 euros per year would be worth it for us 🙂 Especially since I believe the difference will be smaller in the coming years. A new oil heating system would cost around 20,000 euros according to the heating engineer, but I think a heat pump could be installed somewhat cheaper.
Heat pump in a poorly insulated house with radiators doesn’t work.
You typically need a supply temperature of around 60°C (140°F) to get usable heat into the house with radiators. They were usually even designed for 70°C (158°F) or higher.
This becomes extremely inefficient when using a heat pump.
Either replace the oil burner or, better, switch to gas if possible.
Pellets would also be an option, but in my opinion, it’s hardly ever economical.
You typically need a supply temperature of around 60°C (140°F) to get usable heat into the house with radiators. They were usually even designed for 70°C (158°F) or higher.
This becomes extremely inefficient when using a heat pump.
Either replace the oil burner or, better, switch to gas if possible.
Pellets would also be an option, but in my opinion, it’s hardly ever economical.
Hmm, I think the heating system in our house wasn’t properly designed; they just installed a radiator under each window, matching the width of the window. At least the roof (in my opinion the most important part?) is well insulated. I’m also willing to consider further optimization measures, for example, larger radiators could be installed in some rooms without significant drawbacks, and some of the windows need to be replaced anyway.
N
nordanney9 Feb 2021 19:03meowmeow schrieb:
Hmm, I think the heating system in our house wasn’t properly designed; they simply installed a radiator under each window matching the window width. And at least the roof (in my opinion the most important part) is well insulated now. I would also be willing to implement further optimization measures, for example, larger radiators could be installed in some rooms without any significant downsides, and some of the windows need to be replaced anyway.Just for comparison with your unrenovated place: I have to renovate to KFW 55 standard to make heating with a heat pump reasonably effective. Flow/return temperatures are 40/35. Even that was only achievable by upgrading the radiators significantly. The standard outdoor temperature is around -7°C (19°F). In an unrenovated state, you will generate very high electricity costs. Of course, achieving 55°C (131°F) flow temperature is possible, but it comes at a huge efficiency penalty. It’s basically like heating water with an immersion heater.
Alright, does my calculation from earlier hold up? In that case, the financial effort would be quite manageable despite the lower efficiency.
I’m not under the illusion of building a high-efficiency structure here that energy consultants from all over the world would come to admire as a marvel. It’s more about choosing the least bad option among all the inefficient solutions like gas, oil, or heat pump.
I’m not under the illusion of building a high-efficiency structure here that energy consultants from all over the world would come to admire as a marvel. It’s more about choosing the least bad option among all the inefficient solutions like gas, oil, or heat pump.
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