Author Topic: Clearance of in wall rigid metal vent from combustibles  (Read 5463 times)

samting

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Clearance of in wall rigid metal vent from combustibles
« on: December 31, 2012, 04:31:58 PM »
I purchased a DB425 vent for 2x6 construction in basement. The inwall vent will run up to ceiling (approx 7 feet) and with a 90 degree to about 5 feet out the rim joist.

I plan on filling up the cavity with Roxul but the question / concern i have is how close can the in wall vent be to the drywall. That is the ventbox opening suggests the rigid metal vent will virtually run parallel and almost touching the drywall.

An comment on your forum suggested that code doesn't require any clearance of the round vent from combustibles.

I found some comments on this saying 1 inch clearance, but it may not be applicable to interior cavities, but wanted you comments before i complete the enclosure. Thanks!

M1306
CLEARANCES FROM COMBUSTIBLE CONSTRUCTION
M1306.2 Clearance reduction.
Reduction of clearances shall be in accordance with the appliance manufacturer's instructions and Table M1306.2. Forms of protection with ventilated air space shall conform to the following requirements:

1. Not less than 1-inch (25.4 mm) air space shall be provided between the protection and combustible wall surface.

2. Not less than 1-inch (25.4 mm) air space shall be provided between the protection and combustible wall surface.. Air circulation shall be provided by having edges of the wall protection open at least 1 inch (25.4 mm).

3. If the wall protection is mounted on a single flat wall away from corners, air circulation shall be provided by having the bottom and top edges, or the side and top edges open at least 1 inch (25.4 mm).

4. Wall protection covering two walls in a corner shall be open at the bottom and top edges at least 1 inch (25.4 mm).

rickharp

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Re: Clearance of in wall rigid metal vent from combustibles
« Reply #1 on: January 02, 2013, 01:19:04 PM »
Good question, and I agree, Chapter M1300 of the code uses the term "appliance" loosely. 
Section M1502 of the code deals only with Clothes Dryer venting, henceforth because it is dealt with there, then it is regarded in 13 as already been described and spoken for.   
Clearly, dryer ducting does not have a stipulation of clearance to combustibles, be it a wood stud or paper backed drywall. 
The code doesn't require any clearance of the round vent pipe to combustibles.  Hope this helps, feel free to reply or call us.  Thanks
Rick Harpenau
In-O-Vate Technologies, Inc
Jupiter, FL  33477
561-743-8696

samting

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Re: Clearance of in wall rigid metal vent from combustibles
« Reply #2 on: January 02, 2013, 05:09:10 PM »
Thanks for your comments!

I think I will center the 4" round vent in the middle of the 2x6 therefore giving 3/4 inch clearance on each side for most of the run to the top. (ie the round vent will tilt back from the top of the drybox to the center of the stud). Ive just purchased your 90 degree Ell corner vent to attach. Ill fill the cavity with roxul insulation and cover that cavity with metal sheeting ( to dissipate any heat). you indicated the heat level should only be to 155 degrees, so this extra measure should certainly be added protection!
The balance of the 2x6 wall will be insulated with roxul and plastic sheet vapour barrier before I drywall as i live in Canada.

Thanks for your great products!