I have a uninsulatable crawlspace with uninsulated metal ductwork running through it. I have been exploring the options for insulating the ductwork. At the current cost of gas not doing so seems immoral even though this is a rental unit.
The main duct is a rectangle, no I did not crawl under and measure it yet, and the branch runs are mostly 6" rounds.
As expressed by another poster in another thread I feel the bubble wrap foil is bubblecrap. The Hart and Cooley sleeves look like the best bet, with more work for the rounds. But what to use for the main duct and the boots?
There is an R6 product but you have to cut and fit. To really get the R6 it will need to be installed uncompressed. I am not crazy about the thought of dealing with that product in a crawlspace.
I have not found a semi-rigid product that could be applied to the exterior of the main duct. I am thinking something like is on the inside of insulated duct.
Any and all suggestions for the best way and payback for insulating the ductwork is appreciated.
Colbyt