Page 1 of 2 12 LastLast
Results 1 to 13 of 14

Thread: Insulated Vent?

  1. #1
    Join Date
    Aug 2011
    Location
    Fort Mcmurray,Ab
    Posts
    56

    Insulated Vent?

    I have a client who wants me to insulate a flexible chimney vent (7/4) for a gas fireplace because he is worried about condensation where it passes through a cold space before hooking up to the fireplace. I told him it can't be done because I need to keep my clearance to combustibles and insulation is combustible, he says he had one installed before and they used foil back ins. with the foil against the vent and then wrapped again with the foil on the outside . Is this right or am I right in sticking to keeping clearances ? Thanks.

  2. #2
    Join Date
    Aug 2004
    Location
    S.E. Pa
    Posts
    6,192

    Cool

    the code prohibits you from wrapping vents and connnectors. Also, wrapping vents with anything, no matter the fire worthiness, restricts the flow of cooling air thus voids the warranty and listing. You need that air flow to reduce temps. Insulation works--it keeps hot things hot. We want to cool them.

    HTH

  3. #3
    Join Date
    Aug 2011
    Location
    Ontario
    Posts
    381
    No need to insulate 7& 4 will only cause problems. I have hundreds running through unheated attics etc., never been a problem. And its cold here.
    There is no bad beer, some just taste better than others.

  4. #4
    Join Date
    Jun 2008
    Location
    Madison, WI
    Posts
    33
    wood stove exhaust usually is hot enough to not condense. If it was a problem (like you have a low temperature boiler) you could use double-wall exhaust duct. (I'm not sure this is the correct word, but you create an airgap between two pipes that insulates. since both pipes are metal, no issue with combustion). that actually may be necessary to protect any surrounding material from heat. Especially where humans could touch it. Obviously nothing should touch the exhaust duct.

  5. #5
    Join Date
    Aug 2011
    Location
    Ontario
    Posts
    381
    Quote Originally Posted by kaleun View Post
    wood stove exhaust usually is hot enough to not condense. If it was a problem (like you have a low temperature boiler) you could use double-wall exhaust duct. (I'm not sure this is the correct word, but you create an airgap between two pipes that insulates. since both pipes are metal, no issue with combustion). that actually may be necessary to protect any surrounding material from heat. Especially where humans could touch it. Obviously nothing should touch the exhaust duct.
    Not the question. It is a fireplace.
    There is no bad beer, some just taste better than others.

  6. #6
    Join Date
    Aug 2011
    Location
    Fort Mcmurray,Ab
    Posts
    56
    Thanks MANACO I've used ceramic fibre blanket before on welded exhaust duct for a kitchen and It wasn't the easiest material to work with but If that's what he wants, the customer is always right? right!

  7. #7
    Join Date
    Aug 2011
    Location
    Ontario
    Posts
    381
    You best check with manufaturer to see if that may void any warranty.
    There is no bad beer, some just taste better than others.

  8. #8
    Join Date
    Aug 2004
    Location
    S.E. Pa
    Posts
    6,192

    Exclamation don't wrap the pipe unless listed that way!

    It will void the warranty and listing. I sit on the UL Standards Technical Panel that writes the UL listing stds so please trust me--wrapping listed venting is a fire hazard! It isn't so much a matter if the insulation can take the heat or not but that it prevents the venting from cooling. This makes the entire fireplace hotter. Don't do it!!!!

    BTW, most ceramic fiber blanket is rated to about 2,150F before it begins to degrade substantially. CF blankets are routinely wrapped around stainless steel chimney liners and factory chimney listed to UL 1777 and UL 103HT respectively which are 2,100F listings.

    A gas direct vent, which is what the OP described runs about 500-600F--when the pipe is allowed to cool by ambient air.

  9. #9
    Join Date
    Aug 2004
    Location
    S.E. Pa
    Posts
    6,192

    Exclamation

    Manaco, I must advise you, you are giiving out falty hazardous advice here that goes directly against codes, standards, listings and fire science. I am reporting your post and asking you to temper yourself to these stds. You may go freestyle in your own job but this site does not condone advice that contradicts these principles so blatantly with procedures that are known causes of unfriendly fires.

    Again, this is a direct vent gas fireplace that does not and cannot use double walled factory chimney.

  10. #10
    Join Date
    Aug 2011
    Location
    Ontario
    Posts
    381
    Listen to the hearthman, he knows what he speakath.
    There is no bad beer, some just taste better than others.

  11. #11
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,120
    Under review.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  12. #12
    Join Date
    May 2004
    Posts
    12,028

  13. #13
    Join Date
    Nov 2011
    Location
    vancouver island canada
    Posts
    8
    Manufacturers specifications rule! The customer is not always right whcih is why we are called.
    ryan

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event