Ducting Size for ERV (FV-10VEC2)
CDNReno
| Posted in Mechanicals on
Reading through the FV-10VEC2 manual I see that it specs you can use 4″ or 6″ ducts.
My space is limited and thus the 4 inch is appealing, especially for the outside and exhaust air, however I’m wondering if there will be much of a penalty for using 4 inch. Furthermore, I’m very interested in keeping the noise down. Is there a better choice for sound reasons? Does it make sense to go with 6 inch and branch down to 4 inch in rooms? I can make anything work but smaller is easier.
This will be independently ducted system, doing 2 bedrooms, 2 bathrooms and a loft area (plus common area) of about 1200 SF. Climate 7A.
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Replies
Larger duct is usually better for sound. That model ERV can be 50-100cfm. If sticking closer to 50cfm you could likely be ok with 4 inch duct but I would likely still try for a 6 inch trunk reduced to 4 inches if manageable. I went with a mix of 6 and 8 inch ductwork since room was less of an issue and I wasn't sure how high I wanted the CFM, and am glad I didn't go smaller. I mostly run my ERV at 70cfm right now but it's nice being able to boost to 140cfm or more for clearing moisture from bathrooms. With air being pulled from 2 bathrooms, even at 140cfm it's more like 70 per bathroom.