Insulate Supply Line in Attic?
Hi, I’m trying to get a little more efficiency out of my HVAC system and I’m wondering whether to bother with attempting to insulate some supply lines that are in the attic of a commercial building. The attic is within the thermal envelope but it is unconditioned. The attic is used for storage and therefore has a floor. All the supply lines have been mounted flush on top of the floor and I can feel major air leaks at all the seams/connections. My idea is try to slightly lift sections and apply mastic tape to the seams on the bottom as well as apply mastic to the sides and top. Then I started wondering if I could wrap insulation on the ductwork as well if I can slide it under. My concerns are: 1) If I prop the line up too far I risk causing some separation at the seams which may cause more air loss and 2) If the insulation is compressed much(and it will be) it will lose R-value and therefore a diminishing or marginal return.
Should I stick with trying the mastic only, mastic and insulation all around, or mastic and insulation on tops and sides? Or something else I’m missing? For reference I’m in Zone 5 bordering Zone 4, Hot summers, Cold winters.
My apologies if I left anything pertinent out. Thanks in advance!
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