ᐅ Which Heating System to Choose After Replacing a Heating Unit After 30 Years?
Created on: 25 May 2016 14:33
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86biboOur newly acquired property currently has an oil heating system installed. It must be replaced by the end of 2017, as it will then be 30 years old. The tanks are in excellent condition, so only the heating system needs to be replaced. We have two floors plus a basement and an insulated attic. The ground floor has underfloor heating and convectors; the basement (with a basement bar and bathroom) also has convectors, as does the upper floor. The ground floor is designed to be very open, so a lot of heat spreads throughout the house (and thus to the upper floor). The living area is 220m² (2,368 square feet).
The first (and still most favored) idea is to install a new oil heating system. Gas would theoretically be interesting but is unfortunately not available. Heat pumps are out of the question because the insulation is probably not sufficient for that. Since we have a well-oriented roof surface, I considered solar thermal with heating support, but that also depends on the costs, as it usually only just breaks even.
I wonder whether I should seriously consider a pellet heating system. Of course, I am put off by the high investment costs (25,000€ compared to 8,000€ for oil, or 14–15,000€ for oil/solar), and I question whether it will actually pay off over time.
The previous owners’ energy consumption was not good (final energy consumption 143 kWh/m² [42.0 kBtu/ft²]), but they also heated a lot with wood, apparently of low calorific value. Therefore, I think that if one were to heat purely with oil, the energy demand would be somewhat lower. I suspect that with a new pure oil heating system without “wood support,” I will reach 110–120 kWh/m² (32.3–35.3 kBtu/ft²), and with solar thermal may approach 100 kWh/m² (29.4 kBtu/ft²). Is it even worth switching to a pellet heating system in this case?
The first (and still most favored) idea is to install a new oil heating system. Gas would theoretically be interesting but is unfortunately not available. Heat pumps are out of the question because the insulation is probably not sufficient for that. Since we have a well-oriented roof surface, I considered solar thermal with heating support, but that also depends on the costs, as it usually only just breaks even.
I wonder whether I should seriously consider a pellet heating system. Of course, I am put off by the high investment costs (25,000€ compared to 8,000€ for oil, or 14–15,000€ for oil/solar), and I question whether it will actually pay off over time.
The previous owners’ energy consumption was not good (final energy consumption 143 kWh/m² [42.0 kBtu/ft²]), but they also heated a lot with wood, apparently of low calorific value. Therefore, I think that if one were to heat purely with oil, the energy demand would be somewhat lower. I suspect that with a new pure oil heating system without “wood support,” I will reach 110–120 kWh/m² (32.3–35.3 kBtu/ft²), and with solar thermal may approach 100 kWh/m² (29.4 kBtu/ft²). Is it even worth switching to a pellet heating system in this case?
Hi,
if the tanks are really still in good condition and you don’t need the space they occupy, simply replacing the oil burner with an oil condensing boiler will probably be the cheapest and most economical solution.
Everything else will – as you already mentioned – be much more expensive. For the pellet option, you need to create storage space. Whether the costs will ultimately pay off, and by when, is hard to say from here. It might be worth considering if your oil tanks are no longer in good condition.
For a solar thermal system (most likely with heating support) for a 220 sqm (2,370 sq ft) house, you will need about 7-8 sqm (75-86 sq ft) of collector area. To make the system work effectively, choose one with flat tube vacuum collectors (although this increases costs). In our region, such systems generally have very long payback periods. You can safely leave it out, as the savings aren’t significant. Instead, consider installing a photovoltaic system, possibly with a smaller battery storage (5 kWh), which will give you returns sooner.
I would go for the more affordable solution and simply live comfortably. By the way, the energy efficiency of your house is not that bad. There are many, many houses that perform much worse.
Best regards
Thorsten
PS: Based on your calculation above, you save about 400 liters of oil per year with solar thermal, roughly estimated assuming very high efficiency. I would rather say it’s around 270-300 liters. This means the payback period stretches toward the end of the system’s life, especially considering today’s oil prices.
if the tanks are really still in good condition and you don’t need the space they occupy, simply replacing the oil burner with an oil condensing boiler will probably be the cheapest and most economical solution.
Everything else will – as you already mentioned – be much more expensive. For the pellet option, you need to create storage space. Whether the costs will ultimately pay off, and by when, is hard to say from here. It might be worth considering if your oil tanks are no longer in good condition.
For a solar thermal system (most likely with heating support) for a 220 sqm (2,370 sq ft) house, you will need about 7-8 sqm (75-86 sq ft) of collector area. To make the system work effectively, choose one with flat tube vacuum collectors (although this increases costs). In our region, such systems generally have very long payback periods. You can safely leave it out, as the savings aren’t significant. Instead, consider installing a photovoltaic system, possibly with a smaller battery storage (5 kWh), which will give you returns sooner.
I would go for the more affordable solution and simply live comfortably. By the way, the energy efficiency of your house is not that bad. There are many, many houses that perform much worse.
Best regards
Thorsten
PS: Based on your calculation above, you save about 400 liters of oil per year with solar thermal, roughly estimated assuming very high efficiency. I would rather say it’s around 270-300 liters. This means the payback period stretches toward the end of the system’s life, especially considering today’s oil prices.
I believe old oil tanks could also be converted into pellet storage; I read something about that when we were considering whether we could set up a pellet storage system (we couldn’t).
Pellet boilers are available starting from 2,500 euros (Atmos D15p, which can also use firewood), and there is a government grant of 3,000 euros or 3,500 euros with a buffer tank. You only have to add a few euros for installation.
Of course, you can also buy a pellet boiler for 25,000 euros if you want to spend that much.
Or if you can get firewood cheaply, you might want to look into firewood boilers, which are also eligible for government support.
In the end, we chose a pellet boiler for the living area; the boiler alone cost 3,500 euros, and the total cost including installation, new pipes, expansion vessel, and buffer tank was 6,000 euros.
Pellet boilers are available starting from 2,500 euros (Atmos D15p, which can also use firewood), and there is a government grant of 3,000 euros or 3,500 euros with a buffer tank. You only have to add a few euros for installation.
Of course, you can also buy a pellet boiler for 25,000 euros if you want to spend that much.
Or if you can get firewood cheaply, you might want to look into firewood boilers, which are also eligible for government support.
In the end, we chose a pellet boiler for the living area; the boiler alone cost 3,500 euros, and the total cost including installation, new pipes, expansion vessel, and buffer tank was 6,000 euros.
Hello,
As part of our renovation, we are facing a similar question.
Basically, the options would be (gas would have been interesting as well, but unfortunately there is no connection available in the street):
- new oil condensing boiler
- new oil condensing boiler including solar thermal system for heating support
- pellet heating system
The approximate costs would be roughly as follows (just estimates):
- Oil condensing boiler: €8,000
- Solar system (heating support): €10,000 (including buffer tank)
- Pellet system 20kW: €20,000 (including silo storage, condensing technology, buffer tank)
Currently, the tendency clearly leans toward pellets for the following reasons:
- Oil feels somewhat outdated nowadays
- I am no longer really convinced by solar thermal systems (also thanks to this forum), especially regarding their practicality and cost-effectiveness. For a long time, we favored the oil + solar combination (although our roof orientation is not ideal, but would still be feasible)
- Our oil tanks would also need to be renewed/replaced, so an additional €2,000–3,000 would be added to the oil option
- Subsidies for pellet heating systems are currently quite attractive (mainly because the pellet market has slumped due to the oil price). There is a good rebate of €6,900 available from BAFA currently (pellet heating including buffer tank, condensing technology, plus incentive program Energy-efficient APEE). Additionally, there are further incentives in Bavaria (which of course do not apply for 86bibo). Moreover, a pellet system offers better opportunities for potential further KfW energy renovation measures (which we also plan)
- Some acquaintances have installed pellet heating systems and are overall very satisfied so far
In our case, pellets versus oil + solar is roughly comparable in price (pellets might be about €1,000 more expensive). Only oil without solar could cause problems regarding KfW funding.
Personally, I tend to lean more toward pellets overall.
For the original poster, the situation is a bit different (larger price difference between pellets and oil, oil tanks still intact, etc.).
Therefore, I would probably also lean towards just replacing the oil heating system, as Thorsten’s post suggests.
If you haven’t already:
Take a look at the packages from the KfW Program 151 (Energy-efficient Renovation) here (keyword: heating package).
If you want to finance the new oil heating system through this, you might still be able to get a subsidy of 12.5%.
As part of our renovation, we are facing a similar question.
Basically, the options would be (gas would have been interesting as well, but unfortunately there is no connection available in the street):
- new oil condensing boiler
- new oil condensing boiler including solar thermal system for heating support
- pellet heating system
The approximate costs would be roughly as follows (just estimates):
- Oil condensing boiler: €8,000
- Solar system (heating support): €10,000 (including buffer tank)
- Pellet system 20kW: €20,000 (including silo storage, condensing technology, buffer tank)
Currently, the tendency clearly leans toward pellets for the following reasons:
- Oil feels somewhat outdated nowadays
- I am no longer really convinced by solar thermal systems (also thanks to this forum), especially regarding their practicality and cost-effectiveness. For a long time, we favored the oil + solar combination (although our roof orientation is not ideal, but would still be feasible)
- Our oil tanks would also need to be renewed/replaced, so an additional €2,000–3,000 would be added to the oil option
- Subsidies for pellet heating systems are currently quite attractive (mainly because the pellet market has slumped due to the oil price). There is a good rebate of €6,900 available from BAFA currently (pellet heating including buffer tank, condensing technology, plus incentive program Energy-efficient APEE). Additionally, there are further incentives in Bavaria (which of course do not apply for 86bibo). Moreover, a pellet system offers better opportunities for potential further KfW energy renovation measures (which we also plan)
- Some acquaintances have installed pellet heating systems and are overall very satisfied so far
In our case, pellets versus oil + solar is roughly comparable in price (pellets might be about €1,000 more expensive). Only oil without solar could cause problems regarding KfW funding.
Personally, I tend to lean more toward pellets overall.
For the original poster, the situation is a bit different (larger price difference between pellets and oil, oil tanks still intact, etc.).
Therefore, I would probably also lean towards just replacing the oil heating system, as Thorsten’s post suggests.
If you haven’t already:
Take a look at the packages from the KfW Program 151 (Energy-efficient Renovation) here (keyword: heating package).
If you want to finance the new oil heating system through this, you might still be able to get a subsidy of 12.5%.
86bibo schrieb:
The oil tanks could theoretically be removed, and the space used for pellets, but is the room large enough for the 6000-liter (1585-gallon) tanks? Is it possible to install a pellet heating system with automatic feed for €15,000?For that price, definitely double or triple the capacity. For example, the Atmos system can be purchased with the appropriate accessories, such as a 1000-liter (265-gallon) storage tank and up to a 2.5-meter (8.2-foot) auger. That costs around €4,000 or €1,000 after the Bafa subsidy, plus installation. I once requested a quote and it should come to about €2,500 final price (including the subsidy). That is far, far from €15,000.
Of course, there are more expensive pellet boilers that offer one or two additional features, such as a lambda probe, etc. They then cost ten times as much. There is also a wide range of models priced in between. Doing a bit of research is definitely worthwhile. What I liked about the Atmos was its active online community with immediate support in their own forum. Ultimately, however, due to lack of installation space, another company’s boiler was chosen for the living area.