Good day!
I am the type of person who likes to address and solve things before they become a problem. Therefore, I am considering whether there is a sensible way to move away from heating oil without switching to natural gas. Based on some basic data, can you roughly estimate what might be possible?
The total usable area of the house is 300 square meters, of which 178 square meters (about 1917 square feet) is living space. The difference mainly consists of basement rooms, which I partly use for my freelance work. Two adults and one child live in the house; both adults also work from home. We use about 3,000 liters (approximately 792 gallons) of heating oil per year (around 10 liters (2.6 gallons) per square meter including hot water) and consume about 8,000 kWh of electricity, as we also charge two electric cars.
The house is built with 24 cm (9.4 inches) thick solid Liapor elements, which provide excellent thermal buffering: in summer it remains cool for a long time, and in autumn it stays warm for a long time. Outside, there is 6 cm (2.4 inches) of mineral insulation, followed by a 4 cm (1.6 inches) air gap, and then a brick cladding. The wooden windows are double-glazed. The house has a carpentry-style roof structure with 20 cm (7.9 inches) of mineral insulation, and during the interior work we paid close attention to precise airtightness.
The oil-fired central heating system is now 22 years old but still runs very well. We do not have underfloor heating but radiators in every room. The flow temperature is about 40°C (104°F), and we operate a heating curve roughly as flat as that used for underfloor heating. Our roof shape (half-hipped roof with four gable dormers) is not suitable for photovoltaic panels; however, the garage roof (gable roof with about 30° pitch, ridge orientation north-south) offers space for about 70 square meters (around 753 square feet) of photovoltaic panels, half facing east and half west, with no shading from trees. Between the garage and the house, I have already installed a 5x16 square NyY cable (50 meters long (164 feet)) because that is where the cars are charged. So, if photovoltaic panels are installed on the garage roof, the inverter and control system could be housed in the garage, and there is also space beside the garage for battery storage. There is sufficient garden space for ground collectors as well.
Now I am wondering: is there a reasonable overall concept involving photovoltaics, battery storage, heat pump, and flat plate collectors? I would like to remove the oil tank but do not want a gas connection. Under these conditions, is it possible to achieve a relatively high degree of self-sufficiency for much of the year, so that only a small amount of electricity needs to be purchased, while avoiding the risk of running out of heat in cold periods?
Ideally, I would like to commission an independent energy consultant for such a concept, but I have no idea how to find someone who approaches this in a technology-neutral way while keeping an eye on political decisions that, of course, cannot be predicted now regarding how they will develop over the coming years. If you act too early, you might regret it later when stronger subsidies become available; but if you wait too long, you might have to endure rising oil and electricity prices for a longer period. Besides, I simply no longer find it acceptable to burn oil or gas.
Matthias
I am the type of person who likes to address and solve things before they become a problem. Therefore, I am considering whether there is a sensible way to move away from heating oil without switching to natural gas. Based on some basic data, can you roughly estimate what might be possible?
The total usable area of the house is 300 square meters, of which 178 square meters (about 1917 square feet) is living space. The difference mainly consists of basement rooms, which I partly use for my freelance work. Two adults and one child live in the house; both adults also work from home. We use about 3,000 liters (approximately 792 gallons) of heating oil per year (around 10 liters (2.6 gallons) per square meter including hot water) and consume about 8,000 kWh of electricity, as we also charge two electric cars.
The house is built with 24 cm (9.4 inches) thick solid Liapor elements, which provide excellent thermal buffering: in summer it remains cool for a long time, and in autumn it stays warm for a long time. Outside, there is 6 cm (2.4 inches) of mineral insulation, followed by a 4 cm (1.6 inches) air gap, and then a brick cladding. The wooden windows are double-glazed. The house has a carpentry-style roof structure with 20 cm (7.9 inches) of mineral insulation, and during the interior work we paid close attention to precise airtightness.
The oil-fired central heating system is now 22 years old but still runs very well. We do not have underfloor heating but radiators in every room. The flow temperature is about 40°C (104°F), and we operate a heating curve roughly as flat as that used for underfloor heating. Our roof shape (half-hipped roof with four gable dormers) is not suitable for photovoltaic panels; however, the garage roof (gable roof with about 30° pitch, ridge orientation north-south) offers space for about 70 square meters (around 753 square feet) of photovoltaic panels, half facing east and half west, with no shading from trees. Between the garage and the house, I have already installed a 5x16 square NyY cable (50 meters long (164 feet)) because that is where the cars are charged. So, if photovoltaic panels are installed on the garage roof, the inverter and control system could be housed in the garage, and there is also space beside the garage for battery storage. There is sufficient garden space for ground collectors as well.
Now I am wondering: is there a reasonable overall concept involving photovoltaics, battery storage, heat pump, and flat plate collectors? I would like to remove the oil tank but do not want a gas connection. Under these conditions, is it possible to achieve a relatively high degree of self-sufficiency for much of the year, so that only a small amount of electricity needs to be purchased, while avoiding the risk of running out of heat in cold periods?
Ideally, I would like to commission an independent energy consultant for such a concept, but I have no idea how to find someone who approaches this in a technology-neutral way while keeping an eye on political decisions that, of course, cannot be predicted now regarding how they will develop over the coming years. If you act too early, you might regret it later when stronger subsidies become available; but if you wait too long, you might have to endure rising oil and electricity prices for a longer period. Besides, I simply no longer find it acceptable to burn oil or gas.
Matthias
The basement is insulated: the basement walls are made from the same material as the rest of the house, but they stand within a tank made of waterproof concrete. I don’t find 3,000 liters (usually it’s between 2,500 and 2,700) particularly much for 300 square meters. However, I should honestly mention that three basement rooms (unheated) do not have windows but ventilation openings, which I close in winter with a shutter. A fair amount of heat will surely escape there. I did it this way because, during my planning phase, two companies in the same industry run by friends were broken into violently, and these rooms store very expensive equipment. I preferred not to have windows there. Although my windows cannot be broken in easily with reasonable effort, some offenders are not smart enough to realize that and still cause huge damage.
But if the surface area of the radiators is fundamentally too small, then the whole project won’t work anyway, because I don’t want to make major alterations to the house. The basement rooms are also fitted with very complex acoustic wall and ceiling panels, so it’s not easy to simply run new pipes to the upper floors. On the other hand, the heating manifolds on each floor are easily accessible. Still, at the very least, you would have to remove the entire screed (in several rooms it’s wooden floorboards on joists instead) to install underfloor heating and then renovate all the rooms. That would be a major construction site for many months, with horrible noise, dirt, work, and costs. This might be feasible for a secondhand house that was inherited as a fixer-upper, but certainly not for a house that is only about 20 years old.
Perhaps it’s better to wait it out. I always have to see my house in connection with my parents’ house, which stands right next door on the same property and is almost 100 years old. A few years ago, the old oil boiler there was replaced with a new one because my father is not a fan of changes. Since my house stands on his property, it is legally practically his house, so he naturally has a say in such matters. Older people are less resilient, especially when it comes to large construction projects, so I must not overwhelm them. Therefore, only solutions with manageable effort are possible. I understand that none of this will ever pay off financially, except if oil prices multiply. But it’s also about the better feeling of not burning oil anymore.
But if the surface area of the radiators is fundamentally too small, then the whole project won’t work anyway, because I don’t want to make major alterations to the house. The basement rooms are also fitted with very complex acoustic wall and ceiling panels, so it’s not easy to simply run new pipes to the upper floors. On the other hand, the heating manifolds on each floor are easily accessible. Still, at the very least, you would have to remove the entire screed (in several rooms it’s wooden floorboards on joists instead) to install underfloor heating and then renovate all the rooms. That would be a major construction site for many months, with horrible noise, dirt, work, and costs. This might be feasible for a secondhand house that was inherited as a fixer-upper, but certainly not for a house that is only about 20 years old.
Perhaps it’s better to wait it out. I always have to see my house in connection with my parents’ house, which stands right next door on the same property and is almost 100 years old. A few years ago, the old oil boiler there was replaced with a new one because my father is not a fan of changes. Since my house stands on his property, it is legally practically his house, so he naturally has a say in such matters. Older people are less resilient, especially when it comes to large construction projects, so I must not overwhelm them. Therefore, only solutions with manageable effort are possible. I understand that none of this will ever pay off financially, except if oil prices multiply. But it’s also about the better feeling of not burning oil anymore.
B
Benutzer20019 Dec 2021 15:431. Have a heating load calculation performed (Heckmann)
2. Calculate the flow temperature using the largest possible radiators (33mm (1.3 inches))
3. Purchase and install a heat pump
4. Replace radiators
5. Be happy
Discuss photovoltaic systems and storage solutions separately. Unfortunately, I can’t say where, as I have already been blocked for that.
But if a maximum flow temperature of 40°C (104°F) is sufficient, a heat pump will also work.
2. Calculate the flow temperature using the largest possible radiators (33mm (1.3 inches))
3. Purchase and install a heat pump
4. Replace radiators
5. Be happy
Discuss photovoltaic systems and storage solutions separately. Unfortunately, I can’t say where, as I have already been blocked for that.
But if a maximum flow temperature of 40°C (104°F) is sufficient, a heat pump will also work.
Replacing all radiators would be a relatively minor inconvenience and can be done easily throughout our property. However, it’s important to consider a solution for when a room is being renovated and the radiators need to be temporarily removed, as the 33mm (1.3 inches) models will be about one-third heavier.
How can one find an independent consultant in Berlin to discuss all these issues and who can develop a plan that can then be implemented by a heating contractor and a photovoltaic specialist? For example, would the trade association for plumbing, heating, and air conditioning (SHK) be able to recommend someone, at least for the heating side, or do they not provide such services?
Matthias
How can one find an independent consultant in Berlin to discuss all these issues and who can develop a plan that can then be implemented by a heating contractor and a photovoltaic specialist? For example, would the trade association for plumbing, heating, and air conditioning (SHK) be able to recommend someone, at least for the heating side, or do they not provide such services?
Matthias
D
Deliverer19 Dec 2021 18:00tomtom79 schrieb:
I would first check where the oil is actually going. Some of it certainly goes into the old heating system. Especially for domestic hot water in summer, the efficiency of those units is really poor.
Based on the project description, I would also say that a heat pump should work without any problems. You still have a good part of the winter left, so you can carry out the usual transition checks: record daily average temperatures and oil consumption. Set the supply temperature at the heating system initially to 50°C (122°F) — I assume the 40°C (104°F) you mentioned was the current setting, not the maximum supply temperature — and keep all radiators fully open. If it gets too warm, reduce the supply temperature further, down to the minimum. Turn off the night setback. Then you can revisit the project here or in that other forum.
Regarding photovoltaics: there is a good, neutral place where you can get advice on that as well. In short: even “challenging” roofs can often be used to install photovoltaics economically. Plus, you still have a decent garage, so I would definitely explore that option. Please skip storage batteries for now; currently, they are about four times too expensive to be economically viable. High energy self-sufficiency won’t help if it costs more than buying electricity from the grid. Compared to the oil heating, you can at least produce about 25% of your heating energy yourself quite easily. No hassle.
So: nice project, get started!
In der Ruine19 Dec 2021 18:11Deliverer schrieb:
First set the supply temperature of the heating system to 50°C (122°F) – I assume the 40°C (104°F) you mentioned was the current, not the maximum, supply temperature – and keep all radiators fully open. If it gets too warm, lower the supply temperature further, down to the minimum. Turn off the night setback.Is this just for testing, or can I generally set it like this in an older house?Similar topics