Posted by DaveL(inPA) on Monday, October 29, 2007 at 02:46:05 :
In Reply to: Another idea posted by Jerry in Idaho on Sunday, October 28, 2007 at 22:19:53 :
I think your on to it Jerry. I used to to in a place that made duct work for buildings. We had some black insulation that we would line the duct with. It seems to me that it was 1 to 1 1/2 inches thick.
Talk to some HVAC guys