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!
W
WilderSueden10 Jan 2021 21:48If I remember correctly, you only have to replace the heating system when the owner changes, and then immediately. Otherwise, old oil burners are grandfathered in.
And about power outages... how often do they happen? I can manage without heating for 5 minutes a year. Even a longer power outage here rarely lasts more than half an hour, not half a week like in America 😉
Schimi1791 schrieb:The more I look into this topic, the less convinced I am that photovoltaic panels contribute much to a heat pump. In winter, days are short and mostly cloudy, so there isn’t much photovoltaic electricity generated. And when the sun does shine (at least in new buildings with many floor-to-ceiling windows), you actually gain enough heat through solar gains. Also, the wiring seems to be somewhat more complex if you want photovoltaic electricity for general use and a heat pump with a separate meter.
I’m not sure if a heat pump is worth it without photovoltaic panels.
meowmeow schrieb:The main advantage is probably that you don’t need a gas line where it would be prohibitively expensive. There are many people who live much more than 60m (200 feet) away from the gas network. You might also save a few euros by buying at a favorable time compared to a continuous tariff, but that’s probably a minor point.
Does liquid gas from a tank have any advantages over piped gas?
And about power outages... how often do they happen? I can manage without heating for 5 minutes a year. Even a longer power outage here rarely lasts more than half an hour, not half a week like in America 😉
P
pagoni202010 Jan 2021 21:57Ha, great. I actually had exactly this in my house... and it’s still running fine even after the sale.
That’s often the problem. Just read through this forum and you’ll see—it’s something you really need to deal with actively; it’s not a guaranteed solution. Installers often don’t have sufficient expertise, and repairs can be very expensive.
The tank is installed right next to the house or buried underground. You can either buy or rent it... It’s all a matter of calculation. Depending on the situation, it’s definitely worth considering at least once.
meowmeow schrieb:
Hmm, as I understand it, a heat pump usually has an electric heater as a backup since it comes with a heating element, right?
That’s often the problem. Just read through this forum and you’ll see—it’s something you really need to deal with actively; it’s not a guaranteed solution. Installers often don’t have sufficient expertise, and repairs can be very expensive.
meowmeow schrieb:
Does liquid propane from a tank have any advantages over a pipeline supply?
The tank is installed right next to the house or buried underground. You can either buy or rent it... It’s all a matter of calculation. Depending on the situation, it’s definitely worth considering at least once.
pagoni2020 schrieb:
Ha, great. I actually had exactly this in my house... and it still works after I sold it.
That’s often the problem. It’s best to read up here, and you’ll see that you have to deal with it—it’s not something that runs itself. The installers often don’t know much about it, and repairs can be very expensive.
The tank is installed right next to the house or buried. You can either buy or rent it... It all depends on the calculations. Depending on the situation, it’s at least worth considering once. So, the tank basically has no advantages over the pipeline. If you rent, you are tied to the provider you rent from, who can charge any price for refilling.
If you buy, you are required to have it inspected—every 10 years, I think. Whether it’s cheaper than installing 60 m (200 ft) of pipeline... I have no idea.
As a fallback option, only an independent stove without a water connection would be possible.
After a lot of research, my current favorite is a Panasonic split heat pump. Hot water production is handled via a hygiene storage tank with a subsequent instantaneous water heater for hot water generation. Our water is quite hard (21H), and I’m not sure if I need a water softening system.
Additionally, I’m considering a different stove. I haven’t seen it in person yet, but we like the design. Since the stove doesn’t require electricity—unlike a water-based system—we wouldn’t be left without heat during a longer power outage (which hasn’t happened in the last 30 years anyway). In my opinion, a water-based wood stove adds a lot of complexity; my approach is more KISS (keep it simple, stupid).
Depending on calculations and available subsidies, I would add a solar panel system on the roof. The question is whether to place it only on the southwest or also on the northeast side. Later, if battery storage becomes more affordable, I might retrofit some. At the moment, I don’t find any technology truly convincing. Saltwater batteries don’t seem fully developed yet, and I find lithium problematic not only for environmental reasons. During the transition period, I could probably store excess solar power in the hygiene storage tank of the heat pump and thus heat somewhat less at night.
To make the heat pump work well, I might upgrade some radiators (the existing ones are over 30 years old, and there’s room for larger units in some places) and partially switch to better-insulated windows. I have some appointments coming up with heating contractors to get quotes, so we’ll see what they suggest. I’m okay with paying about 10% more annually if it means having a cool wood stove in the living room and no stress with gas deliveries or pipelines.
I’m still unclear about heat pump electricity tariffs. With the hygiene storage tank as a buffer, it might work, but I’m concerned that power cutoffs could occur exactly during peak grid load times, around midday, when pumping would be most beneficial.
Currently, there’s a 45% subsidy plus possibly a small additional bonus from the district. What do you think will happen with this in the next few years? I’m not in urgent need to act right now, but the heating system could fail at any time, and inflation might also suggest dealing with this sooner rather than waiting until the coming summers.
Additionally, I’m considering a different stove. I haven’t seen it in person yet, but we like the design. Since the stove doesn’t require electricity—unlike a water-based system—we wouldn’t be left without heat during a longer power outage (which hasn’t happened in the last 30 years anyway). In my opinion, a water-based wood stove adds a lot of complexity; my approach is more KISS (keep it simple, stupid).
Depending on calculations and available subsidies, I would add a solar panel system on the roof. The question is whether to place it only on the southwest or also on the northeast side. Later, if battery storage becomes more affordable, I might retrofit some. At the moment, I don’t find any technology truly convincing. Saltwater batteries don’t seem fully developed yet, and I find lithium problematic not only for environmental reasons. During the transition period, I could probably store excess solar power in the hygiene storage tank of the heat pump and thus heat somewhat less at night.
To make the heat pump work well, I might upgrade some radiators (the existing ones are over 30 years old, and there’s room for larger units in some places) and partially switch to better-insulated windows. I have some appointments coming up with heating contractors to get quotes, so we’ll see what they suggest. I’m okay with paying about 10% more annually if it means having a cool wood stove in the living room and no stress with gas deliveries or pipelines.
I’m still unclear about heat pump electricity tariffs. With the hygiene storage tank as a buffer, it might work, but I’m concerned that power cutoffs could occur exactly during peak grid load times, around midday, when pumping would be most beneficial.
Currently, there’s a 45% subsidy plus possibly a small additional bonus from the district. What do you think will happen with this in the next few years? I’m not in urgent need to act right now, but the heating system could fail at any time, and inflation might also suggest dealing with this sooner rather than waiting until the coming summers.
Well, now during the next warm period, upgrade the house accordingly. Make the heating surface as large as possible and carry out energy-efficient renovations. This benefits any heating system.
Next winter, test how low you can go with the flow temperature (VLT). Then decide which system makes the most sense.
Next winter, test how low you can go with the flow temperature (VLT). Then decide which system makes the most sense.
N
nordanney5 Feb 2021 09:33meowmeow schrieb:
Hot water generation via a hygienic storage tank combined with a downstream instantaneous water heater.Why use an instantaneous water heater? Panasonic units can generally operate down to -15°C (5°F) without an electric heating element. It would be simpler to install an electric heating element as a backup in the hygienic storage tank, so it only activates when strictly necessary (controlled by the heat pump).meowmeow schrieb:
I am still unclear about the value of heat pump electricity tariffs.Generally, none.Similar topics