We're getting ready to replace the heat-pump system in our 25 year old house.  Before we do, I'd like to clean and vapor sealing the duct work.  I'd be sincerely interested in any thoughts or comments on the value of doing so.

If it's worthwhile, how do you locate a contractor to vapor seal the ducts -- lots of people do duct cleaning, but I've not found any that list sealing.

Very respectfully,
Larry

Larry,

Have you considered getting a price for spraying closed cell polyurethane on the ducts.  I have seen this done and it seems to seal and insulate quite well.

Alton,

Thanks for a good idea that I'll keep in mind when I build (still 4 years out).  Unfortunately, I'm still in my 25 year old house, and I only have access to the ducts immediately above the air-handler.  I've found the name of the product -- Aeroseal -- which Carrier bought out several years ago.  The attractive point is that you seem to only need limited access to the ducts.  But my impression is that it's expensive (I was quoted $1,500 to clean and then Aeroseal the ducts).  So. . .  I was hoping that someone had tried it.

Very respectfully,
Larry