Payback on Duct Insullation

[CJT]

Are you sure? I thought the necessary air gap consisted of the air in the bubbles. Otherwise what's the point of the bubbles?

[HeatMan]

Yes, I'm sure. The bubbles hold the air inside the air space.

Install one piece correctly and the other in the haphazard way you mentioned. Get a surface reading thermometer from Radio Shack(no, I don't have a link) and 'shoot' the insulation. I'll bet you see a warmer surface on the haphazard Reflectix.

[sherwindu]

I have checked further with the web site of Reflectix, which I should have done in the first place. They claim their insulation gives about a 4.2 R value if applied with no air gap, as opposed to the R-6 value with a single air gap. This value goes up to an even higher value of about R-15 if a second layer with another air gap is applied.

I somewhat fault the company for show> > HeatMan wrote: