ᐅ Location of the central ventilation unit

Created on: 15 Oct 2018 21:14
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HausbauTiNa
Hello everyone,

In our new build (gable roof house, 182 m² (1960 ft²), finished attic) we are installing a central ventilation system.

Since we have a carport next to the utility room, our architect prefers not to install the ventilation unit in the utility room due to concerns about exhaust fumes, stale air, etc.

Instead, the system is planned to be installed in the finished attic. We have some concerns about noise and sound transmission throughout the building, especially since a children’s bedroom is located directly under the attic.

What are your thoughts on this issue?
How do you access the filters of the intake duct on the roof?

Thank you in advance.
tomtom7916 Oct 2018 15:26
@Lumpi_LE

The units are actually quiet; ours is no louder than a fan.

And out of the 6 houses on our street, only 2 have an uninsulated roof.
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Lumpi_LE
16 Oct 2018 15:34
Maybe depending on the region, I have hardly ever seen the attic insulated here. Our ventilation system is already quite loud at full power, and I haven’t found others that are much quieter. But that’s just my opinion—I wouldn’t have wanted that thing on the roof. Since we have a LEWT, it wouldn’t be possible anyway, or even more impractical.
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Alex85
16 Oct 2018 18:22
Who would voluntarily build a cold roof? You need insulation anyway, so the extra cost of adding it to the roof structure is minimal, while the gain in usable space is significant.

I wouldn’t worry about noise either; it can’t really be worse than having the system in a room on the living floor.

A ventilation system almost never runs at full capacity when it is properly sized.
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Bookstar
16 Oct 2018 20:36
Alex85 schrieb:
Who would voluntarily build a cold roof? You need insulation anyway, so the extra cost to include it in the roof is minimal, while the gain in usable space is considerable.
I wouldn’t worry about noise either; it can’t be much worse than having the system in a room on the living floor.

A ventilation system almost never runs at full capacity if it’s properly sized.

A cold roof is cheaper, because polystyrene costs almost nothing. Proper insulation on top of the roof or between rafters costs several thousand more.

You can hear some noise directly below, but not significantly more than if it’s installed on the ground floor.
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Lumpi_LE
16 Oct 2018 20:55
That doesn’t make sense. Programs for “shock ventilation,” for example in the morning and evening, are useful because the system then runs close to its maximum capacity. In summer, the system can be used for cooling, which also works with an air exchange rate of 1, which for a single-family house controlled ventilation system is “full throttle.”
Extending the insulation all the way up to the ridge has the advantage of frost-free storage space, but that’s about it. The disadvantages are that you need to ventilate that area, or it can lead to serious problems; it is more expensive to install, and, although minimally, it increases heating costs.
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Alex85
16 Oct 2018 21:45
What’s supposed to be sensible about that? An air change rate of 0.4 per hour is several times higher than what a person would normally achieve through ventilation. Trying to apply a power function on top of that... well.

The extra cost for a warm roof might be around 3,000 (currency). That’s a total bargain for the increased usability of that space (for example, heating or ventilation can be installed there instead of taking up space in the living floors).