Insulated plenum in conditioned space?
My wife and I are completing a large addition. We have tried to follow many GBA tips for building a good and energy efficient house.
We are having a problem with the HVAC contractor.
When he bid the job he said “No problem” to everything, but then in the middle he kept trying to cut corners.
He did fix some things in the middle when I complained, but now he’s done and it’s still sub-par.
We did all new ducts and systems. He bid it as a typical install in an unconditioned space.
We did spray foam at the roof and made the attic a conditioned space halfway through the job. We blocked the ridge and eve venting and sprayed.
His air leakage is above 7% on the brand new ducting! New ducting should be below 6%, but he says he doesn’t have to since it’s in a conditioned space.
He didn’t insulate the plenum. He says he doesn’t have to, since it’s in a conditioned space.
I understand the per code, doing the minimum he doesn’t have to insulate the plenum.
Is there any value in insisting he insulate the plenum? [I’ve found some documentation to insist he tries to fix the air leakage (although I won’t turn down more ammo!).]
To me, it seems logical to insulate the plenum. I’ve been in the attic and it’s still warmer than the house. I’d guess 10 degrees or so.
I’d also like to reiterate that we paid for a full install in an unconditioned space. I’m not trying to make him do extra work for free.
Also, we paid a good amount. There were bids that came in decently lower. We paid for “quality”, or so we thought.
I appreciate your help!
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