Bubble wrap vs fiber glass/ -CASTURBO
I don't know what market area the HO is in, but here in Southern Indiana the bubble wrap and fiber glass are very close in cost.
You may want to get a quote from your contractor for the bubble. I wouldn't assume the bubble is much more than the customary wrap.
I've heard that the reflectrix isn't as high an r-value, but like any product will not perform if not installed correctly. It needs an airspace to work correctly.
I've found by experience that you can't stick a pc tape to the duct to hold it as you wrap around. The temporary piece, if it extends beyond the overlap will act as a heat sink (foil tape) and the insulation will sweat right at that spot.
I got a roll one time of a reflectrix type wrap that had a foam micro bubble core, rather than the bubble wrap. The surface temp on the new was the same as the fiberglas duct wrap on the old duct.
There's also a product called aeroflex, I think, like rubatex that is rated for duct wrap use, even exterior exposure. Very good r-value, but pricey.
questions asked, answers received, ignorance abated
liners are more for sound than thermal- the bubble-wrap type is really more economical as far as installation alone-really a breeze and much easier than fiberglass for the same R-4, just needs a stapler, easier to cut, and not much price increase around me.
Read carefully!! Reflectix and other bubble wrap like it is primarily a reflective barrier. To achieve the R6 rating they advertise, it needs to be installed with an air space. The air is the insulator!
Quote from the Reflectix site: 2) Secure spacers every 24” to 36” around ducting, fastening the spacers with UL181 approved HVAC foil tape. This will provide the necessary air space for the most effective use of Reflectix®. Reflectix® spacer product is recommended.