On 29 Apr 2007 19:36:37 -0700, wrote:

Can someone please give me or point me to a decent description of what
construction methods are allowed for air returns in a residential
application? If you're going to refer me to the code, please cite
volume, chapter and verse for me...

Specifically, are we still allowed to box in the space between a
couple of floor joists as part of a return air run? If not, what else
*can* be done?


If the joist bays are open enough for you to box them in,
aren't they open enough for you to shove rectangular metallic
duct in there?