We've just installed a rather expensive set of return air ducts as part of our new hvac retrofit and the contractor says he doesn't plan to test them for leaks. Is this normal?
I'm a bit worried since they run through an unsealed, dirt floored, crawlspace and any leaks will suck lots of nasty stuff into the system.
Yes ,it's standard,though I understand your concern.
He should know ,since he just installed them,IF they sealed them or not.I would have thought his first responce would have been ,"not to worry,masticed or taped all joints,so no leaks".
For the rest of your ducts http://www.aeroseal.com Fix A Flat for your duct system.
I trust that you have pvc covering the dirt!
that the ventilation to crawl is sealed off.
that it has a dehumidifier there --
so YOU will know, look!
the joints between duct section should be sealed as stated.
for returns & supply ducts & plenums, likewise any holes.
harvest rainwater,make SHADE,R75/50/30= roof/wall/floor, use HVAC mastic,caulk all wall seams!