Hello
My wife and I are currently planning to build a one-and-a-half-story single-family house. We have already done extensive research, so we basically know quite well what we want ... and what we don't. The only question giving us some trouble is choosing the best heating system for us, especially because we find very conflicting opinions online on every aspect.
I will try to describe our starting point and what we would decide on based on our current knowledge. I hope there are some people here who can offer us advice and/or guidance.
By default, the house we have chosen is designed with a solar thermal system on the roof (for hot water) and a gas condensing boiler. What we have definitely decided on is underfloor heating (supply temperature 35°C (95°F)).
Last week, I had a consultation with the consumer advice center on this topic, and they recommended expanding the heating system to include an air-to-water heat pump and using the gas boiler as a backup for very cold days. So the air-source heat pump would run as long as outdoor temperatures are above freezing, and the gas boiler would heat when temperatures drop below 0°C (32°F), because the efficiency of an air-source heat pump decreases rapidly below freezing. For the transitional period, they also suggested a fireplace, which is not an issue since my wife wants one anyway.
In addition to the heating circuit described, we would like an automatic ventilation system with heat recovery. With our current knowledge, I would prefer the decentralized version. On the one hand, the initial investment is lower than with a central system (and very likely also the maintenance costs), and on the other hand, my uncle has a similar system in his house and has never reported any negative experiences.
I don't have the exact roof dimensions at hand right now, but the house has external measurements of 9m x 10m (30 ft x 33 ft) and a 45° pitched roof. By rough calculation, one half of the roof offers about 65m² (700 ft²) of space. We have been considering whether it makes sense to use only about two-thirds of that area for solar thermal and the rest for photovoltaic panels. This way, we could produce some of the electricity needed by the air-source heat pump ourselves.
That’s all I can think of for now.
We appreciate any advice, as I’m quite sure we have simply overlooked some points in our considerations so far. Also, I assume there are users here who know more about this than we do and have considerably more practical experience.
Best regards from the very sunny North!
My wife and I are currently planning to build a one-and-a-half-story single-family house. We have already done extensive research, so we basically know quite well what we want ... and what we don't. The only question giving us some trouble is choosing the best heating system for us, especially because we find very conflicting opinions online on every aspect.
I will try to describe our starting point and what we would decide on based on our current knowledge. I hope there are some people here who can offer us advice and/or guidance.
By default, the house we have chosen is designed with a solar thermal system on the roof (for hot water) and a gas condensing boiler. What we have definitely decided on is underfloor heating (supply temperature 35°C (95°F)).
Last week, I had a consultation with the consumer advice center on this topic, and they recommended expanding the heating system to include an air-to-water heat pump and using the gas boiler as a backup for very cold days. So the air-source heat pump would run as long as outdoor temperatures are above freezing, and the gas boiler would heat when temperatures drop below 0°C (32°F), because the efficiency of an air-source heat pump decreases rapidly below freezing. For the transitional period, they also suggested a fireplace, which is not an issue since my wife wants one anyway.
In addition to the heating circuit described, we would like an automatic ventilation system with heat recovery. With our current knowledge, I would prefer the decentralized version. On the one hand, the initial investment is lower than with a central system (and very likely also the maintenance costs), and on the other hand, my uncle has a similar system in his house and has never reported any negative experiences.
I don't have the exact roof dimensions at hand right now, but the house has external measurements of 9m x 10m (30 ft x 33 ft) and a 45° pitched roof. By rough calculation, one half of the roof offers about 65m² (700 ft²) of space. We have been considering whether it makes sense to use only about two-thirds of that area for solar thermal and the rest for photovoltaic panels. This way, we could produce some of the electricity needed by the air-source heat pump ourselves.
That’s all I can think of for now.
We appreciate any advice, as I’m quite sure we have simply overlooked some points in our considerations so far. Also, I assume there are users here who know more about this than we do and have considerably more practical experience.
Best regards from the very sunny North!
Just very generally speaking. Everything you install for heating and energy systems has to pay off at some point. From an economic perspective, installing a particular system only makes sense if the savings it generates eventually exceed the purchase and maintenance costs.
However, that does not necessarily mean that operating the system may not be sensible from an ecological point of view.
However, that does not necessarily mean that operating the system may not be sensible from an ecological point of view.
N
nordanney28 Jul 2013 20:18Now you only need an oil heating system and a pellet boiler. Then you would have every possible heating option installed in your house.
But is this really sensible, and how much would it cost? Solar thermal system + photovoltaic system + gas boiler + air source heat pump + fireplace (hydronic?) are definitely not cheap together and probably will never pay off. Just get proper advice.
As drivers, you don’t use a convertible for summer, a sedan for winter, a sports car for fast driving, and a station wagon for the family.
That’s what your heating plan sounds like. 🙄
But is this really sensible, and how much would it cost? Solar thermal system + photovoltaic system + gas boiler + air source heat pump + fireplace (hydronic?) are definitely not cheap together and probably will never pay off. Just get proper advice.
As drivers, you don’t use a convertible for summer, a sedan for winter, a sports car for fast driving, and a station wagon for the family.
That’s what your heating plan sounds like. 🙄
When I see some photovoltaic systems covering the entire roof, it must be that the technology only pays off with a large surface area. I think it costs around 15,000 (maybe even more).
Then you don’t really need solar anymore. Solar seems to be the most cost-effective way for home builders to offer a house according to the 2009 Energy Saving Ordinance / building code. That’s all it really is. If alternative systems are installed, you might be able to do without it, but I would definitely plan to include a provision for it later on.
A lot of technology also means a significant amount of additional space for installation. A technical room takes up quite a bit of space; in a standard house without a basement, the utility room could become cramped.
Controlled mechanical ventilation is never a bad idea... I’m not sure about decentralized systems, but those could also cost around 8,000.
A chimney with a fireplace is about 10,000.
Underfloor heating 5,000.
And then two heating systems... Wow.
I would rather invest in a wellness bathroom from one heating system 🙂
Then you don’t really need solar anymore. Solar seems to be the most cost-effective way for home builders to offer a house according to the 2009 Energy Saving Ordinance / building code. That’s all it really is. If alternative systems are installed, you might be able to do without it, but I would definitely plan to include a provision for it later on.
A lot of technology also means a significant amount of additional space for installation. A technical room takes up quite a bit of space; in a standard house without a basement, the utility room could become cramped.
Controlled mechanical ventilation is never a bad idea... I’m not sure about decentralized systems, but those could also cost around 8,000.
A chimney with a fireplace is about 10,000.
Underfloor heating 5,000.
And then two heating systems... Wow.
I would rather invest in a wellness bathroom from one heating system 🙂
B
Bauexperte29 Jul 2013 11:53Hello,
Oh man – if this keeps up, I probably won’t be recommending the consumer advice center anymore 😕
Before you install this whole (nonsensical) system in your house—as long as your budget even allows it—there are other systems I would consider instead! I don’t know why the consumer advisor offered you this “belt-and-braces” setup, but I suspect it reflects their interpretation of dealing with the 2014 Energy Saving Ordinance.
If the conditions of the planned building project—including external factors—permit, a gas condensing boiler with solar domestic hot water (or alternatively the 15% solar share rule), proper insulation under the floor slab, and a decentralized ventilation system with heat recovery are generally sufficient to achieve a KfW 70 efficiency house standard. Gas is, by the way, not a bad choice given the current confusing price trends, as its cost is expected to stabilize favorably in the medium term due to newly tapped sources. The underfloor heating, which is mandatory to install, also allows for connecting renewable technologies after the lifespan of the gas condensing boiler. This way, any builder is given time to observe the maturity and practicality of current technologies over their lifecycle.
To say that an air-to-water heat pump “needs belt and braces” is quite something! It’s true that it’s not suitable for every building project yet; but it’s equally true that, where a proper calculation is made, it performs well! With technology, it’s like building materials: not every technology fits every building project universally. We have clients who are very satisfied with their air-to-water heat pump, especially regarding maintenance costs.
Regarding photovoltaics—you have probably missed the boat here. In earlier times—when modules were more expensive—such systems generated good returns. Today, with reduced incentives, the situation looks very different. In my personal view, photovoltaics only make sense if you have high self-consumption and storage options. Then you have to carefully weigh the pros and cons of the currently known storage media; the costs are also significant if you want something other than a lead-acid battery.
In short—find a trustworthy energy consultant and discuss the options for “your” house. I’m quite sure that after this conversation, you’ll just shake your head at the proposals made by the person mentioned at the beginning.
Best regards,
Bauexperte
AoR schrieb:
By default, the house we have chosen is built with a solar thermal system on the roof (for hot water) and a gas condensing boiler. What we have definitely decided on is underfloor heating (supply temperature 35°C (95°F)).
Last week, I had a consultation with the consumer advice center about this topic, and they recommended expanding the heating system with an air-to-water heat pump and using the gas boiler as a backup for very cold days. So, the air heat pump would run as long as outdoor temperatures are above freezing, and gas heating would be used at subzero temperatures because the efficiency of an air-to-water heat pump drops sharply below 0°C (32°F). For the transition period, they also suggested a fireplace, which isn’t a problem for us since my wife wanted one anyway.
Oh man – if this keeps up, I probably won’t be recommending the consumer advice center anymore 😕
AoR schrieb:
In addition to the described heating circuit, we would like an automatic ventilation system. Based on what I know so far, I would prefer the decentralized version with heat recovery. On one hand, the upfront costs are lower than for a centralized system (and most likely also the maintenance costs), and on the other hand, my uncle has a similar system in his house and reported no negative experiences.
I don’t have the exact roof dimensions on hand, but the house footprint is 9m x 10m (30ft x 33ft approx.) with a 45° pitched roof. According to my rough calculations, one side of the roof has about 65m² (700ft²) of space. We were wondering whether it might make sense to use only about two-thirds of that area for solar thermal and the rest for photovoltaics. This way, we could produce some of the electricity needed for the air heat pump ourselves.
Before you install this whole (nonsensical) system in your house—as long as your budget even allows it—there are other systems I would consider instead! I don’t know why the consumer advisor offered you this “belt-and-braces” setup, but I suspect it reflects their interpretation of dealing with the 2014 Energy Saving Ordinance.
If the conditions of the planned building project—including external factors—permit, a gas condensing boiler with solar domestic hot water (or alternatively the 15% solar share rule), proper insulation under the floor slab, and a decentralized ventilation system with heat recovery are generally sufficient to achieve a KfW 70 efficiency house standard. Gas is, by the way, not a bad choice given the current confusing price trends, as its cost is expected to stabilize favorably in the medium term due to newly tapped sources. The underfloor heating, which is mandatory to install, also allows for connecting renewable technologies after the lifespan of the gas condensing boiler. This way, any builder is given time to observe the maturity and practicality of current technologies over their lifecycle.
To say that an air-to-water heat pump “needs belt and braces” is quite something! It’s true that it’s not suitable for every building project yet; but it’s equally true that, where a proper calculation is made, it performs well! With technology, it’s like building materials: not every technology fits every building project universally. We have clients who are very satisfied with their air-to-water heat pump, especially regarding maintenance costs.
Regarding photovoltaics—you have probably missed the boat here. In earlier times—when modules were more expensive—such systems generated good returns. Today, with reduced incentives, the situation looks very different. In my personal view, photovoltaics only make sense if you have high self-consumption and storage options. Then you have to carefully weigh the pros and cons of the currently known storage media; the costs are also significant if you want something other than a lead-acid battery.
In short—find a trustworthy energy consultant and discuss the options for “your” house. I’m quite sure that after this conversation, you’ll just shake your head at the proposals made by the person mentioned at the beginning.
Best regards,
Bauexperte
In addition to the air-to-water heat pump, I have also had a wall outlet installed for a stainless steel chimney in case it turns out that the heat pump is either insufficient or too expensive to operate. This is not costly, and it allows you to easily and relatively inexpensively retrofit an additional heating source for the living areas in the form of a wood stove, if it actually becomes necessary.
I am somewhat skeptical about the photovoltaic system. Your roof area is relatively small, and you also have to consider that usually only one side (and perhaps not even the entire side) can be used. This means that only a small portion of your own electricity demand can be covered, and as mentioned before, feeding excess power back into the grid is no longer as financially attractive.
I am somewhat skeptical about the photovoltaic system. Your roof area is relatively small, and you also have to consider that usually only one side (and perhaps not even the entire side) can be used. This means that only a small portion of your own electricity demand can be covered, and as mentioned before, feeding excess power back into the grid is no longer as financially attractive.
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