Hello everyone,
maybe someone here can give us a good tip, as we are quite uncertain about a ventilation system.
We are planning to build a house (solid construction) according to KfW 70 standards, with underfloor heating, a fireplace, and a solar system. That much is already decided.
We received an offer from Company A for a ventilation system with heat recovery, and the salesperson recommended it to us.
At Company B, the ventilation system is significantly more expensive, and the salesperson told us that since the house is so well insulated, moisture would not be an issue... where would it come from? The rest could be regulated by normal airing anyway.
(I also think he realized that his ventilation system would have blown our budget and now I worry that he advised us against it just for that reason!)
My husband and I are laypersons, but my instinct tells me that the better the house is insulated, the more problems I would have getting rid of moisture and stale air inside the house, right?
After all, a blower door test does show that there is very little air circulation.
Am I completely wrong?
We are a bit torn now, since such a system is not exactly cheap! But is it necessary, or just a nice extra?
Thank you very much for your help!
maybe someone here can give us a good tip, as we are quite uncertain about a ventilation system.
We are planning to build a house (solid construction) according to KfW 70 standards, with underfloor heating, a fireplace, and a solar system. That much is already decided.
We received an offer from Company A for a ventilation system with heat recovery, and the salesperson recommended it to us.
At Company B, the ventilation system is significantly more expensive, and the salesperson told us that since the house is so well insulated, moisture would not be an issue... where would it come from? The rest could be regulated by normal airing anyway.
(I also think he realized that his ventilation system would have blown our budget and now I worry that he advised us against it just for that reason!)
My husband and I are laypersons, but my instinct tells me that the better the house is insulated, the more problems I would have getting rid of moisture and stale air inside the house, right?
After all, a blower door test does show that there is very little air circulation.
Am I completely wrong?
We are a bit torn now, since such a system is not exactly cheap! But is it necessary, or just a nice extra?
Thank you very much for your help!
Hi,
Is there still a homeowner today who admits to building without a mechanical ventilation system with heat recovery?
Whether and how these systems actually work has become almost secondary; the main thing is that I have my single-family house equipped with mechanical ventilation.
However, there are certainly planners who, after weighing all the details, hold a different view. There are also homeowners who do not miss the absence of mechanical ventilation.
Best regards, fmjuchi
Is there still a homeowner today who admits to building without a mechanical ventilation system with heat recovery?
Whether and how these systems actually work has become almost secondary; the main thing is that I have my single-family house equipped with mechanical ventilation.
However, there are certainly planners who, after weighing all the details, hold a different view. There are also homeowners who do not miss the absence of mechanical ventilation.
Best regards, fmjuchi
B
Bauexperte12 Feb 2011 10:29Hello €uro,
I honestly don’t know whether to laugh or be annoyed.
Aside from the fact that the first part of that sentence is an irresponsible nonsense in itself – less airtight houses would cause fewer problems and require less, increasingly expensive technology – the second part shows complete naivety. Today’s buildings are so airtight that simple window ventilation often no longer suffices, especially in times when open floor plans or higher ceiling heights are very popular _and_ particularly when both partners are working full time. This heat and moisture buildup becomes especially problematic where a non-opening window is installed in an open space.
Knowing that there are quite a few bad actors among home sellers, I reject being placed under general suspicion with the implied suggestion that commissions explain the support for ventilation systems. Those affected by humidity problems will be pleased to know whether you stand ready to compensate anyone harmed by your statement that "simple window ventilation is still fully sufficient for standard buildings (Energy Saving Ordinance, KfW 70)."
No technician has yet convinced me of the benefits of controlled ventilation with heat recovery in “standard” homes (below KfW 55 efficiency levels), but anyone who, like me, has repeatedly experienced results of 0.7 or lower in a blower door test reacts very sensitively to the blanket statement that in KfW 70 efficient houses, fear of mold has been turned into a mantra.
Kind regards
€uro schrieb:
Modern buildings are relatively airtight, which makes sense and is necessary. However, simple window ventilation is often still sufficient for standard buildings (Energy Saving Ordinance, KfW 70), even though the business of fear around mold is booming.
I honestly don’t know whether to laugh or be annoyed.
Aside from the fact that the first part of that sentence is an irresponsible nonsense in itself – less airtight houses would cause fewer problems and require less, increasingly expensive technology – the second part shows complete naivety. Today’s buildings are so airtight that simple window ventilation often no longer suffices, especially in times when open floor plans or higher ceiling heights are very popular _and_ particularly when both partners are working full time. This heat and moisture buildup becomes especially problematic where a non-opening window is installed in an open space.
Knowing that there are quite a few bad actors among home sellers, I reject being placed under general suspicion with the implied suggestion that commissions explain the support for ventilation systems. Those affected by humidity problems will be pleased to know whether you stand ready to compensate anyone harmed by your statement that "simple window ventilation is still fully sufficient for standard buildings (Energy Saving Ordinance, KfW 70)."
No technician has yet convinced me of the benefits of controlled ventilation with heat recovery in “standard” homes (below KfW 55 efficiency levels), but anyone who, like me, has repeatedly experienced results of 0.7 or lower in a blower door test reacts very sensitively to the blanket statement that in KfW 70 efficient houses, fear of mold has been turned into a mantra.
Kind regards
Bauexperte schrieb:
Today’s houses, built according to the latest technology standards and the requirements of the Renewable Energy Heat Act as well as the Energy Saving Ordinance, are so airtight that regular ventilation usually isn’t enough to remove moisture from the house. Keep in mind – especially if both you and your husband are working – when will you be able to ventilate?I generally think a ventilation system is a good idea, but I disagree with the idea that moisture cannot be removed from the house just because you are working.
If you ventilate well once more in the morning before going to work, the moisture is already mostly gone.
If no one is in the house during the day, no moisture should build up (unless the apartment is full of plants).
Best regards
H
Holzwurm3013 Feb 2011 08:53Hello everyone,
We also have a mechanical ventilation system with heat recovery (Pluggit) in our new build (prefabricated house KfW 70 standard)!!!
I have to say, we wouldn’t want to be without it now.
There is nothing better than waking up in the morning in the bedroom with fresh, clean air throughout the room and the entire house. Why wouldn’t you want to continue using the energy you pay for in the house (bathroom/kitchen)?
At first, we were a bit skeptical about whether we should install it, as we couldn’t imagine never having to open the windows again — is that really possible? But it really is, and it provides a fantastic indoor climate throughout the whole house at a low cost (electricity consumption about 96 euros per year).
Best regards
We also have a mechanical ventilation system with heat recovery (Pluggit) in our new build (prefabricated house KfW 70 standard)!!!
I have to say, we wouldn’t want to be without it now.
There is nothing better than waking up in the morning in the bedroom with fresh, clean air throughout the room and the entire house. Why wouldn’t you want to continue using the energy you pay for in the house (bathroom/kitchen)?
At first, we were a bit skeptical about whether we should install it, as we couldn’t imagine never having to open the windows again — is that really possible? But it really is, and it provides a fantastic indoor climate throughout the whole house at a low cost (electricity consumption about 96 euros per year).
Best regards
Hello,
Who plans or does such nonsense? First, creating a moisture and heat buildup, and then suggesting the builder install a mechanical ventilation system to fix the problem. Clearly, there is not much expertise here.
Best regards.
Bauexperte schrieb:Just pick whichever suits you best.
...I really don’t know whether to laugh or be annoyed
Bauexperte schrieb:
... This heat and moisture buildup becomes especially problematic where a non-opening window is installed in the air space.
Who plans or does such nonsense? First, creating a moisture and heat buildup, and then suggesting the builder install a mechanical ventilation system to fix the problem. Clearly, there is not much expertise here.
Bauexperte schrieb:Ah, yes—I forgot, everything is just gifts and completely selfless.
implicit suggestion that there is a commission for the ventilation system as well.
Bauexperte schrieb:There are no moisture problems when the necessary requirements are properly clarified. Apparently, you fail at this and prefer to sell a mechanical ventilation system instead.
Those affected by moisture problems will be glad,.....
Bauexperte schrieb:There is no need to convince anyone. You just have to be able to understand and comprehend. If you can’t do that, then simply omit heat recovery for your clients.
...No technician has yet convinced me of controlled ventilation _with_ heat recovery in “normal” house construction (< KfW 55)....
Best regards.
B
Bauexperte14 Feb 2011 10:00Hello €uro,
don’t worry about my competence; I can look at myself in the mirror every morning with a clear conscience.
I am fully capable of performing a heat demand calculation and, in this context, also a cost-benefit analysis. Especially regarding the latter, heat recovery in a single-family house built to KfW 70 standard is not very effective—measured by the energy saved compared to the increased investment costs. So your sarcasm misses the mark, particularly because I make sure to inform every potential homeowner about the advantages and disadvantages as well as cost-effective alternatives and involve trade-specific experts in the discussions. If they choose the latter option, by the way, my compensation for the service I provided ends there. However, you probably won’t understand the motivation behind this; based on your education, I guess I expected too much.
Kind regards
don’t worry about my competence; I can look at myself in the mirror every morning with a clear conscience.
I am fully capable of performing a heat demand calculation and, in this context, also a cost-benefit analysis. Especially regarding the latter, heat recovery in a single-family house built to KfW 70 standard is not very effective—measured by the energy saved compared to the increased investment costs. So your sarcasm misses the mark, particularly because I make sure to inform every potential homeowner about the advantages and disadvantages as well as cost-effective alternatives and involve trade-specific experts in the discussions. If they choose the latter option, by the way, my compensation for the service I provided ends there. However, you probably won’t understand the motivation behind this; based on your education, I guess I expected too much.
Kind regards
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