ᐅ Which wall assembly is suitable for being vapor-permeable?
Created on: 15 Mar 2021 12:34
H
Hausbauer2021
Hello everyone,
I am currently researching wall construction with a focus on vapor-open systems. I am very concerned about mold growth in the house, which is why I have often read that a vapor-open build is preferable (using a vapor retarder instead of a vapor barrier). However, when I look at the wall constructions of various manufacturers, a vapor barrier is often installed rather than a retarder (for example, Danwood). If the mechanical ventilation system fails, does this then inevitably lead to mold growth? Can anyone share their experience with how this (PE foil) actually performs in a house? Are there wall constructions where a mechanical ventilation system is installed as a nice-to-have but not essential? We currently live in an apartment and have to air the rooms multiple times in winter to prevent mold from forming under the blinds’ boxes. Are there houses or walls that do not experience these problems? We definitely want a ventilation system, but I would like to avoid the worry of mold growth within a few days if the system fails.
Thank you very much for your experiences.
I am currently researching wall construction with a focus on vapor-open systems. I am very concerned about mold growth in the house, which is why I have often read that a vapor-open build is preferable (using a vapor retarder instead of a vapor barrier). However, when I look at the wall constructions of various manufacturers, a vapor barrier is often installed rather than a retarder (for example, Danwood). If the mechanical ventilation system fails, does this then inevitably lead to mold growth? Can anyone share their experience with how this (PE foil) actually performs in a house? Are there wall constructions where a mechanical ventilation system is installed as a nice-to-have but not essential? We currently live in an apartment and have to air the rooms multiple times in winter to prevent mold from forming under the blinds’ boxes. Are there houses or walls that do not experience these problems? We definitely want a ventilation system, but I would like to avoid the worry of mold growth within a few days if the system fails.
Thank you very much for your experiences.
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nordanney16 Mar 2021 13:29Hausbauer2021 schrieb:
Sounds really good, may I ask who the general contractor was?You can install those yourself or any window manufacturer will supply the windows with rebate ventilation for a minimal extra cost.
bauenmk202016 Mar 2021 13:30Hausbauer2021 schrieb:
What are the specifics, if I may ask?* Do not block the window sills * Floor-to-ceiling windows and pets (Where did the dog suddenly go?)
* Cross ventilation during strong winds can blow the papers off your desk
* For effective ventilation, the external roller shutter should be raised -> more frequent roller shutter operations
...
This applies to manual window ventilation. In contrast, window frame ventilators provide a minimum level of ventilation. However, the air exchange rate probably cannot be measured.
Other "disadvantages" include:
* Noise infiltration
* Possible water ingress during heavy rain against the window. The water then runs along the inside of the frame and exits again through the drainage openings.
We have never had any issues with water. The wind is constant and not bothersome; you get used to it. The cat always comes back, and having the window slightly open works well too. All in all, no problems.
So, dear Controlled Mechanical Ventilation owners, let’s get to the point. Extra cost? How often does it break down? How much electricity does it use? How do the pipes get insulated? Don’t stay silent, brothers—speak up, we want to hear.
So, dear Controlled Mechanical Ventilation owners, let’s get to the point. Extra cost? How often does it break down? How much electricity does it use? How do the pipes get insulated? Don’t stay silent, brothers—speak up, we want to hear.
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nordanney16 Mar 2021 13:50Nordlys schrieb:
So, dear owners of mechanical ventilation with heat recovery, let’s get to the point. Extra cost? How often does it break? How much electricity does it use? How dirty do the ducts get? Don’t stay silent, brothers, speak up, we want to hear. Cost: 2,400 € (about $2,600) for self-installation of a decentralized mechanical ventilation with heat recovery system. Experience from a central mechanical ventilation with heat recovery system: never broken, extra cost for a 300 sqm (3,230 sq ft) house around €8,000 (about $8,700). No clogged ducts. BUT: no continuous air flow. Savings on heating costs easily offset the electricity costs. Achieving a good KfW energy rating with window-frame ventilation is difficult to impossible.
The KfW rating and the blower door test are done without the fans, and just like that, the apprentice carpenter comes by and after 15 minutes, they’re done....
nordanney, you can do the math. Your heating cost savings have to be weighed against the electricity costs and the eight thousand for the purchase.
What I see is the gain in comfort. We still need to ventilate to get rid of cooking odors or similar; the controlled ventilation system should be able to handle that. Our 99-euro range hood, for example, doesn’t remove much. It’s more of a design element.
nordanney, you can do the math. Your heating cost savings have to be weighed against the electricity costs and the eight thousand for the purchase.
What I see is the gain in comfort. We still need to ventilate to get rid of cooking odors or similar; the controlled ventilation system should be able to handle that. Our 99-euro range hood, for example, doesn’t remove much. It’s more of a design element.
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