I have a heat pump and I had the main trunk moved in preparation for finishing my basement. The trunk is attached to the bottom of the first floor joists. The finished trunk contains portions of the old trunk and some new sections. The old sections have the insulated duct board inside and the new sections have no insulation.
I have two concerns:
1) Energy inefficiencies with the new duct. Because there is no insulation.
2) Sound traveling to other areas of the house because there is no insulation.
I am thinking of wrapping the trunk with the wrap insulation that can be purchased at a home center. Or I was thinking of attaching insulation foam board to the duct.
I am looking for comments on my proposed solutions and/or looking for other solutions.
Thanks in advance.
Replies
Once upon a time, almost all duct installed in commercial buidings was lined with 1 to 2 inches of faced fiberglass insulation. Very uncommon in a residence. Lined duct is quieter and has a great deal less heat transfer than unlined duct. Whoever did this home originally knew or was a professional tinner. It wouldn't have survide a competitive bid, even with hacks and flex excluded.
If the duct runs are in an unconditioned space, then by all means, wrap them. Commonly available duct wrap is 1-1/2" foil-faced fiberglass. The duct wrap will provide no significant sound deadening, though. Unless there are problems, sound transmission/migration in a residential system is seldom a problem with modern equipment.