Jump to content

Return air

Richard Stanley

Recommended Posts

Around here, wiring is permitted to pass through return air cavities.

E3804.7 Air handling-stud cavity and joist spaces. Where wiring methods having a nonmetallic covering pass through stud cavities and joist spaces used for air handling, such wiring shall pass through such spaces perpendicular to the long dimension of the spaces.

Link to comment
Share on other sites

In the 2003 IMC

Section 602.2.1 Materials exposed within plenums.

There is a list of items that cannot be installed in plenums (please note, a plenum is not a duct). However, under exceptions;

3) This section shall not apply to materials exposed within plenums in one- and two-family dwellings.

The only area (that I could find) that mentions materials in ducts is;

601.3 Contamination prevention.

Exhaust ducts under positive pressure, chimnys and vents shall not extend into or pass through ducts or plenums.

Here's a question:

Does anyone know the difference between a flexible air duct & a flexible air connector?



Link to comment
Share on other sites

Don't forget that the codes are not the answer for everything. Codes are the minimal standard, and not always the best standard.

A return air chase should be clean and sealed, but it provides an easy access to the attic for anyone looking to install something. It is the favorite hiding place for alarm horns and the like.

As for refrigerant lines in a return chase just think about the problems that could arise. The first that jumps out is a condensation problem and all of the water that could collect and start a breeding ground for mold. So the contractor insulates the lines with neoprene foam sleeves. Now we have introduced foam that produces toxic gases when it burns, into the return air.

Link to comment
Share on other sites

Originally posted by BlackJack

Download Attachment: icon_photo.gif Slide36.JPG

92.61 KB

Looking up to the 2nd floor. Horiz. Gas Furnace in 2nd floor closet.

That return air chase doesn't appear to be sealed. It looks like return air is coming from through wall cavities and all kinds of places that might deliver who knows what. There are more problems than the gas piping and wiring.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...