Hello dear community,
we have installed a decentralized ventilation system from Südwind (Ambientika smart). The advantages, such as always having fresh air, fewer pollen particles inside the house, and noise protection thanks to closed windows, are really appealing. However, the costs for purchasing and installing the units are definitely not cheap!
The contractor told us that we can save on heating costs and that the investment pays off within 10 years. Is that possible? I mean, these systems – even with heat recovery – still consume electricity, and we still need to heat the house, right? On top of that, there are maintenance costs (new filters, etc.).
Has anyone done a detailed calculation or has knowledge about the numbers?
we have installed a decentralized ventilation system from Südwind (Ambientika smart). The advantages, such as always having fresh air, fewer pollen particles inside the house, and noise protection thanks to closed windows, are really appealing. However, the costs for purchasing and installing the units are definitely not cheap!
The contractor told us that we can save on heating costs and that the investment pays off within 10 years. Is that possible? I mean, these systems – even with heat recovery – still consume electricity, and we still need to heat the house, right? On top of that, there are maintenance costs (new filters, etc.).
Has anyone done a detailed calculation or has knowledge about the numbers?
I assume you installed the decentralized system during a renovation. It’s clear that the initial effort here is lower than running ductwork throughout the entire house (as with a central system). Of course, this comes at the expense of efficiency.
I can only agree with the previous speakers that calculating this is not straightforward and depends on too many factors to make reliable statements. If we assume that in the end (maybe after about 15 years) you break even, it is still a good investment because you have significantly better air quality, no mold/pollen/dirty air inside the house, and most likely have done something beneficial for your health.
I can only agree with the previous speakers that calculating this is not straightforward and depends on too many factors to make reliable statements. If we assume that in the end (maybe after about 15 years) you break even, it is still a good investment because you have significantly better air quality, no mold/pollen/dirty air inside the house, and most likely have done something beneficial for your health.
Lüftermax schrieb:
I assume you installed the decentralized system during a renovation. [...], because this way you get significantly better air quality, no mold/pollen/dirty air inside the house, and most likely you have done something beneficial for your health. Decentralized systems are better in the sense that every section of ductwork can also become a breeding ground for anything that passes through the filter. See https://www.hausbau-forum.de/threads/160m2-einfamilienhaus-in-holzstaenderbauweise-am-nordhang-mit-keller.28614/page-9#post-279190
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Papierturm10 Jun 2025 16:56Another point besides mold prevention and heat recovery: Nearby, there is a residential area with definitely above-average fine dust and soot levels. I know a few people there. Those who have built or live in homes with ventilation systems (whether centralized or decentralized) have completely unblemished walls.
Everyone without ventilation has to repaint their walls every few years because otherwise, they start to look really worn out.
I don’t know how significant this effect is in a typical residential area. It’s certainly much less pronounced. Still, I found it impressive and can imagine that depending on the location, you might have to repaint less frequently over the years.
Everyone without ventilation has to repaint their walls every few years because otherwise, they start to look really worn out.
I don’t know how significant this effect is in a typical residential area. It’s certainly much less pronounced. Still, I found it impressive and can imagine that depending on the location, you might have to repaint less frequently over the years.
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nordanney10 Jun 2025 17:27Papierturm schrieb:
I’m not sure how significant this effect is in a typical residential area.Living in the countryside, I can confirm it. There is much less dust indoors – you still notice when the tractors are in the fields and/or when straw and hay are being harvested.M
MachsSelbst10 Jun 2025 20:08Well, that might be true if you built in the East End of London in the 1870s.
Regarding the question of whether it’s worth it... is building a new single-family home worthwhile? Is an energy-efficient renovation of an existing property for 200,000 or 300,000 EUR worth it? No. For 300,000 EUR, you can heat for 50 years at 6,000 EUR per year.
The advantage is that you basically don’t need to ventilate anymore. The downside, especially with decentralized systems, is that in summer you constantly bring in heat and, above all, humid air, while in winter the air is usually too dry.
Regarding the question of whether it’s worth it... is building a new single-family home worthwhile? Is an energy-efficient renovation of an existing property for 200,000 or 300,000 EUR worth it? No. For 300,000 EUR, you can heat for 50 years at 6,000 EUR per year.
The advantage is that you basically don’t need to ventilate anymore. The downside, especially with decentralized systems, is that in summer you constantly bring in heat and, above all, humid air, while in winter the air is usually too dry.
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nordanney10 Jun 2025 20:50MachsSelbst schrieb:
The disadvantage, especially with the decentralized system, is that in summer you constantly bring in heat and, above all, humid air.Is it completely different with a central system? Even decentralized systems have cross-flow heat exchangers and bypass options.Similar topics