ᐅ Insulated Older Building from 1921: Converting from Gas Heating
Created on: 8 Mar 2022 11:44
W
Winniefred
Hello dear forum members,
We have been thinking for a while about what to do with our heating system in the long term. Of course, I have already read a lot, but we still don’t have a clear decision.
- The house is a well-insulated old building from 1921, a single-family semi-detached house. Currently, it is heated exclusively with gas; the boiler dates from 2010, is serviced annually, and is working perfectly.
- There is a two-flue chimney; one flue is connected to the gas heating system, the other is free.
- We currently use just under 11,000 kWh of heating energy per year; electricity consumption is about 2,200 kWh/year.
- The roof is a hipped roof, facing east, south, and west, with no shading at all. To put it plainly, it gets full sun all day long.
- The house is fully basemented, and we have quite a lot of space in the cellar, which has a floor area of approximately 40 m² (430 ft²). It is a vaulted cellar with enough headroom to stand comfortably. Slightly damp, consistent with the building’s age.
- We do not have any underfloor heating anywhere. The radiators are modern, some installed as recently as 2017. The house has a timber frame construction, masonry walls, the roof is very well insulated (2017), the facade was well insulated in 1993, and the wooden beam ceilings are filled with slag. The windows are almost all well insulated from 2017, with only three still having double glazing from 1993.
We would like to avoid heating with fossil fuels. At the moment, I’m leaning toward a pellet boiler combined with solar thermal.
Does anyone have other ideas?
We have been thinking for a while about what to do with our heating system in the long term. Of course, I have already read a lot, but we still don’t have a clear decision.
- The house is a well-insulated old building from 1921, a single-family semi-detached house. Currently, it is heated exclusively with gas; the boiler dates from 2010, is serviced annually, and is working perfectly.
- There is a two-flue chimney; one flue is connected to the gas heating system, the other is free.
- We currently use just under 11,000 kWh of heating energy per year; electricity consumption is about 2,200 kWh/year.
- The roof is a hipped roof, facing east, south, and west, with no shading at all. To put it plainly, it gets full sun all day long.
- The house is fully basemented, and we have quite a lot of space in the cellar, which has a floor area of approximately 40 m² (430 ft²). It is a vaulted cellar with enough headroom to stand comfortably. Slightly damp, consistent with the building’s age.
- We do not have any underfloor heating anywhere. The radiators are modern, some installed as recently as 2017. The house has a timber frame construction, masonry walls, the roof is very well insulated (2017), the facade was well insulated in 1993, and the wooden beam ceilings are filled with slag. The windows are almost all well insulated from 2017, with only three still having double glazing from 1993.
We would like to avoid heating with fossil fuels. At the moment, I’m leaning toward a pellet boiler combined with solar thermal.
Does anyone have other ideas?
Winniefred9 Mar 2022 16:52CC35BS38 schrieb:
With a 75°C (167°F) supply temperature, a heat pump is not really suitable. Ideally, you should aim for less than 40°C (104°F) at an outdoor temperature of 0°C (32°F). In general, underfloor heating, ceiling heating, or wall heating systems are more efficient. Since that’s usually not feasible in older buildings without major renovations, you can use Type 33 radiators, which have a larger heat output surface than Type 22, for example. This allows you to lower the supply temperature, which saves costs. I’m still researching this myself, so I can’t easily help with your specific heating system. The first step would be to reduce the supply temperature or adjust the heating curve. This also improves efficiency with gas heating. Then you can see whether the insulation is sufficient for a heat pump and whether you can lower the supply temperature enough. But that only works when it’s cold. The thing is, we only installed 8 new radiators in 2017, but unfortunately they are Type 12 and 22. Only in the children’s rooms are there still 2 older radiators from 1993, plus one in the basement (which I have only used once for a few weeks in the last 5 years).
D
Deliverer10 Mar 2022 10:50The Federal Ministry for the Environment proposed just two weeks ago to gradually ban pellets due to fine dust and CO2 emissions. We are therefore approaching the end of this technology. There has not been enough pellets produced in Germany for many years, and currently, the suppliers from Romania are not really exploiting resources either. So no, pellets are not a viable alternative.
Heat pumps can be installed in any house, sometimes with more effort, sometimes with less. The suggested heating load calculation mentioned earlier should definitely be the first step. Combined with photovoltaic panels covering ALL roof surfaces, this is the only future-proof heating solution.
Go for it. It is currently receiving very strong incentives!
Heat pumps can be installed in any house, sometimes with more effort, sometimes with less. The suggested heating load calculation mentioned earlier should definitely be the first step. Combined with photovoltaic panels covering ALL roof surfaces, this is the only future-proof heating solution.
Go for it. It is currently receiving very strong incentives!
Winniefred10 Mar 2022 12:12Deliverer schrieb:
The Federal Ministry for the Environment proposed just two weeks ago to gradually phase out pellets due to fine dust and CO2 emissions. So we are nearing the end of this technology. There have not been enough pellets produced in Germany for many years, and currently, Romania isn’t really exploiting their resources either. So no, pellets are not a sustainable alternative.
Heat pumps can be installed in any house, with varying levels of effort. The heat load calculation recommended earlier should definitely be the first step. Combined with photovoltaic panels covering ALL roof areas, this is the only future-proof heating system.
Go for it. It is currently very well subsidized! Thank you for your opinion. Yes, and pellets are also steadily becoming more expensive.
I am currently helping friends on their construction site where they are renovating a house from 1977. They are also installing a heat pump with photovoltaic panels. However, they still have the original radiators and are renovating right now, so they are basically able to overhaul everything. Underfloor heating is planned for the ground floor, and new radiators will be installed upstairs.
You can also set the flow temperature yourself. If it unexpectedly gets cold again, you can simply turn it back down. It should work with the instructions; just record a video of what you’re doing so you can undo it if necessary. This way, you can also see what’s possible with the current radiators. I think starting at 50°C (122°F) is reasonable.
I’m not very experienced with insulation, but 20cm (8 inches) sounds good and is better than the 9.3cm (3.7 inches) standard it used to be.
I’m not very experienced with insulation, but 20cm (8 inches) sounds good and is better than the 9.3cm (3.7 inches) standard it used to be.
D
Deliverer10 Mar 2022 12:58Winniefred schrieb:
They have now planned underfloor heating on the ground floor and new radiators will be installed upstairs.If it’s not too late, I would avoid that. A mixed operation is not recommended. You need a buffer tank AND it has to be maintained at the high temperatures required for the radiators.Winniefred10 Mar 2022 15:10CC35BS38 schrieb:
You can also adjust the flow temperature yourself. If it unexpectedly gets cold again, you can simply turn it back up. It should be possible using the instructions—just record what you do so you can reverse it if necessary. That way, you can also see what’s possible with the current radiators. I think starting at 50°C (122°F) is reasonable.
Regarding insulation, I’m not an expert, but 20cm (8 inches) sounds good and is definitely better than the 1993 standard. The heating system was serviced only a few months ago, so I’d rather not adjust anything myself. I’m comfortable with DIY and we do a lot of work on our own, but we’re not confident handling the gas heating system ourselves.
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