Hello everyone
We are currently taking the next steps toward building our own home. We have looked at several prefabricated houses and spoken with sales consultants from various providers. Based on this, we have created a top 5 list. Now I want to contact these 5 companies with our floor plan and the standards we want. This way, I hope the list will be reduced by 2-3 providers after receiving the first offers.
In my inquiry, I want to roughly outline what we have in mind. KFW55, KFW40, or KFW40+ is not yet very important—it will be one of these standards. Our floor plan does not differ much from the standard layouts offered by prefab house suppliers. Something like a simple 8x10 meter (26x33 feet) rectangular shape... To be able to compare the 5 offers reasonably, I want them all to be as similar as possible. Therefore, I would like to specify the heating system.
Now the question is, what is the right choice… I assume this is partly a matter of philosophy? The options are an air-to-water heat pump, an air-to-air heat pump, or a ground-source (geothermal) heat pump. I assume most have one of these three systems combined with solar panels on the roof.
My first thought was this: an air-to-air heat pump, since we would also have an automatic ventilation system in the house, making manual airing less or unnecessary. However, I have learned that all KFW-certified houses are so well insulated that they almost always have automatic ventilation. So this argument is no longer valid. Nevertheless, I still find the air-to-air heat pump interesting. We also want to install a wood stove in the living room. With an air-to-air heat pump, the indoor air is circulated throughout the house, so I could benefit from the wood stove’s heat everywhere, right? Perhaps even with heat recovery, which is usually included.
Another advantage of the air-to-air heat pump would be that if it ever gets too warm, we could install a fixed air conditioning unit somewhere in the house, and the whole house would benefit. The built-in cooling systems in these heat pumps usually aren’t as effective as promised.
Is it true that an air-to-air heat pump cannot provide domestic hot water? Then a second system would be needed just for hot water, which means more costs, two systems to maintain, and more space taken up. In the forum, I mostly see air-to-water heat pumps mentioned, probably combined with underfloor heating. That seems to be the most popular system. Is there a particular reason for this?
Geothermal heating combined with a heat pump seems to be the most efficient. But then I would also have underfloor heating, right? We actually didn’t want underfloor heating, but as I’m writing this, I’m starting to convince myself toward geothermal or air-to-water heat pumps…
How did you make your decision and why? Somehow, I don’t fully trust the salespeople, since they want to sell what makes more money, right? And since I’m not very technical in this area, I’m hoping to benefit from your experience.
Best regards Andreas_79
We are currently taking the next steps toward building our own home. We have looked at several prefabricated houses and spoken with sales consultants from various providers. Based on this, we have created a top 5 list. Now I want to contact these 5 companies with our floor plan and the standards we want. This way, I hope the list will be reduced by 2-3 providers after receiving the first offers.
In my inquiry, I want to roughly outline what we have in mind. KFW55, KFW40, or KFW40+ is not yet very important—it will be one of these standards. Our floor plan does not differ much from the standard layouts offered by prefab house suppliers. Something like a simple 8x10 meter (26x33 feet) rectangular shape... To be able to compare the 5 offers reasonably, I want them all to be as similar as possible. Therefore, I would like to specify the heating system.
Now the question is, what is the right choice… I assume this is partly a matter of philosophy? The options are an air-to-water heat pump, an air-to-air heat pump, or a ground-source (geothermal) heat pump. I assume most have one of these three systems combined with solar panels on the roof.
My first thought was this: an air-to-air heat pump, since we would also have an automatic ventilation system in the house, making manual airing less or unnecessary. However, I have learned that all KFW-certified houses are so well insulated that they almost always have automatic ventilation. So this argument is no longer valid. Nevertheless, I still find the air-to-air heat pump interesting. We also want to install a wood stove in the living room. With an air-to-air heat pump, the indoor air is circulated throughout the house, so I could benefit from the wood stove’s heat everywhere, right? Perhaps even with heat recovery, which is usually included.
Another advantage of the air-to-air heat pump would be that if it ever gets too warm, we could install a fixed air conditioning unit somewhere in the house, and the whole house would benefit. The built-in cooling systems in these heat pumps usually aren’t as effective as promised.
Is it true that an air-to-air heat pump cannot provide domestic hot water? Then a second system would be needed just for hot water, which means more costs, two systems to maintain, and more space taken up. In the forum, I mostly see air-to-water heat pumps mentioned, probably combined with underfloor heating. That seems to be the most popular system. Is there a particular reason for this?
Geothermal heating combined with a heat pump seems to be the most efficient. But then I would also have underfloor heating, right? We actually didn’t want underfloor heating, but as I’m writing this, I’m starting to convince myself toward geothermal or air-to-water heat pumps…
How did you make your decision and why? Somehow, I don’t fully trust the salespeople, since they want to sell what makes more money, right? And since I’m not very technical in this area, I’m hoping to benefit from your experience.
Best regards Andreas_79
M
Myrna_Loy30 Jul 2021 10:31untergasse43 schrieb:
Just google "forest." Among other things, it says that depending on the type, it can regrow fairly quickly. Maybe that will improve your mood.We have forests; I know how fast they grow. I also know how much work it takes to turn a 15m (50 feet) beech tree into firewood. And all of that just for the appearance? I don’t bake a cake only to look at it and then throw it away.
untergasse4330 Jul 2021 10:34There you go. Do you know what happens to your cake after eating and a few hours of peristalsis? Congratulations.
Otherwise, bake your cake and let people enjoy their open fire. You probably don’t have to chop their firewood yourself.
Otherwise, bake your cake and let people enjoy their open fire. You probably don’t have to chop their firewood yourself.
Myrna_Loy schrieb:
We have forest, so I know how fast it grows. I also know how much work it takes to turn a 15 m (50 feet) beech tree into firewood. And all of that just for the look? I don’t bake a cake only to look at it and then throw it away. So why did you build a house then? It seems totally wrong from an ecological point of view if you care so much about the environment. Especially when you consider a) space usage, b) soil sealing (concrete slab), and c) material consumption... It’s better to live in a modern apartment building.
What was that saying about people in glass houses and throwing stones?
A tree that takes hundreds of years to grow and can absorb a lot of CO2 is sacrificed within hours just for appearance, simply because people have not yet aligned their dream house expectations with the currently built high-efficiency construction methods. Even the smallest fireplace already exceeds the heating demand of an entire house, and all that heat is concentrated in a single room. Open the windows and enjoy.
R
RotorMotor31 Jul 2021 07:37@Acof1978 You keep repeating that one shouldn't build at all then. Of course, building has an environmental impact, and a single-family home more so than an apartment block. However, many people cannot avoid building. Therefore, the focus should be on choosing the "right energy concept" within the desired parameters. One that harms the environment the least without any significant loss of comfort.
I don’t understand either. Just use the stove heat like everyone else does. A stove with a lot of thermal mass and an opening into the hallway or similar.
You will regret it a lot if you don’t use the comfortable heat for the house. Especially a heat pump can be a comfort killer because of its slow response combined with underfloor heating.
Without a wood stove, I think my wife would have moved to a hotel many times by now 😀
You will regret it a lot if you don’t use the comfortable heat for the house. Especially a heat pump can be a comfort killer because of its slow response combined with underfloor heating.
Without a wood stove, I think my wife would have moved to a hotel many times by now 😀