Is there an average size for dedicated fresh air duct.?
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Doing a retrofit of a older home, plan to install and ERV and was wondering if there was an average/standard size of duct work. I know manufactures instructions should be followed. Can pvc at $11/10’x4″ be used instead of hvac solid pipe 4″ x60″ / $11. Will have to run in attic but planning to cover with 35 inches of cellulose.
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Chuck,
Practically speaking, I'm sure it works but I would question the airsealing method. I know I wouldn't use PVC glue on anything I rely on for fresh air, and I'm not sure duct sealing mastic would maintain a bond over time. Maybe it does, but I would want assurance from a manufacturer. Good luck with that.
A more fun way of saying that: "choose your pookey wisely!" ;)
4" and 6" are common. Size to the ERV specs for the intake and exhaust ports.