Insulating Rigid Ducts in attic space - best practices?
We run into a lot of uninsulated ducts in our hot Arizona
attics. I would like to know other peoples best practices for insulating -
products and retrofit techniques.
I am well aware that it would be best to move ducts into
conditioned space, so let's save that for another thread - this is for the
customers that do not have that sort of budget but also do not want to leave
them uninsulated.
My first design is using a 2" R8 batt which comes in 4'
widths - Knauf Friendly Feel® Duct Wrap and fastening with Zip-Ez fasteners. I
am thinking of either sealing the seam with butyl tape or duct mastic.
How about one of the bubble wrap products?
How do you deal with duct runs sitting directly on bottom
chords?
Bubble wrap is
nothing but marketing BS, and the FG isn't even going to be close to R8 when
you get it installed
First I would fix
the duct leakage, air seal the attic area under & around the ducts &
dense pack cellulose under the duct
Wrap duct with
foam board on 3 sides - 2 layers offsetting your seams & corners (Liquid
Nail actually holds pretty well & not much is needed, though that product
you listed may work ok also) - finish off sealing all seams &edges with
special UL listed HVAC tape
And
if you want to do job and some othe professional activity then contact on the
call experts http://www.thecallexperts.com
