Ducts in crawlspace

Should ducts be ran into crawl spaces? Could this cause a moisture problem?


All ducts need to be vented to the outside.

I agree with William. No if’s and or butts.

This looks like an abandoned duct and, possibly too large to be an exhaust duct (but potentially from a kitchen downdraft exhaust). However, I’d be recommending having the crawlspace cleaned in accordance with with Residential Construction Performance Guidlines.

Up here I have seen “supply” ducts in basement and crawlspaces to temper the air space. I would have a real problem if there was a return… just an observation…

Johnston Home Inspection

If it’s carrying conditioned air, it should be insulated.f its providing outside air to the system, I wouldn’t accept it. Either way, a referral to a specialist seems appropriate.

I run the furnace when I’m in the crawl space. Helps to find leaks in ducts and you would certainly find out of this duct was active (looks like an abandoned HVAC duct to me).