Results 1 to 8 of 8
  1. #1
    Join Date
    Oct 2003
    Location
    Washington
    Posts
    7,405
    I installed about 15 feet of 5 by 8.( Five inch exhaust inside of 8 inch intake) for a direct vented mendota fireplace. My question is. Should the exterior of the pipe be as hot as say the B-vent for a gas furnace. I would think not, didn't seem right to me. Anyone know what the limits are as far as how hot it should get? Thanks for any info.

  2. #2
    Join Date
    Mar 2005
    Location
    South/West of Quebec in the other part of Canada
    Posts
    2,331
    don't know what the limits are, but is this a horizontal vent application? did you use adequate spacers in your installation? Best bet is to call the manufacture, they have all the stats on their equipment..

    good luck

  3. #3
    Join Date
    Oct 2003
    Location
    Washington
    Posts
    7,405
    It is about 5 feet horizontal and 5 feet vertical. The clearance is fine, just seems it should be cooler than it was, maybe I'm wrong.

  4. #4
    Join Date
    May 2005
    Location
    Madison, WI
    Posts
    1,078
    its hot air coming out, it gets too hot to touch within a few minutes usually. Usually the only way it would get overheated is if its not drafting correctly, like if the air is going out too slow due to not enough coming in. But with the direct vented units you should be able to notice the flames aren't right if the draft is bad.

  5. #5
    Join Date
    Apr 2002
    Posts
    1,383
    You should have the fireplace and the installation inspected by a repairman. Getting opinions on the internet about such a problem doesn't cut it.

    There can be a serious problems that would create the symptoms you describe, such as an overfired burner. Such things could cause a fire or other problems.


    Seattle Pioneer

  6. #6
    Join Date
    Jan 2002
    Location
    New Hampshire
    Posts
    1,285

    or...............

    Recirculating exhaust gasses could be heating the intake.

    Have it serviced before you have carbon monoxide problems, or a building fire.

    It might be a problem.

    Noel

  7. #7
    Join Date
    Aug 2004
    Location
    S.E. Pa
    Posts
    6,273

    ANSI test stds.

    In the testing, 3/4" plywood painted flat black is boxed in around the Fp and venting. With thermocouples every 6 inches, the various test iterations are run. If any thermocouple rises more than 90F above the ambient room temp., the test fails and they have to relocate the plywood farther away at that point. This is how the clearances to combustibles are derived. With an exhaust stack temp. around 600F, the outer pipe can exceed 200F, which is more than enough to burn your hand, so don't grab hot pipe. For this reason, hot venting pipes, whether B-vent, UL 103HT factory chimney, UL127 fireplace chimney, or DV pipe must all be protected from people and people from the pipe.

    The mfrs. instructions are part of the listing. If you comply with the instruction, you comply with the listing. You can buy a set of ANSI Z21.88 (DV Room Heaters)for about $900.00 . Ridiculous, isn't it?

    I agree with S/P and Noel--nothing to play around with. Your doctor can't fix you over the phone and we can't inspect or fix Fps over the internet. You may have installed it perfectly in accordance with the listed instructions but still, it was made by man. Not meant to sound harse-- just firm. We care.

    HTH,

  8. #8
    Join Date
    Oct 2003
    Location
    Washington
    Posts
    7,405
    Hey guys,
    Don't make such a fuss. I fixed the pipe myself. Was fixing one of my fellow installers jobs that he screwed up. I just wasn't aware that DV pipe from a fireplace got extremely hot on the outside considering the intake is enveloping the exhaust. I am sure the installation is fine. I'm just one of those people that checks and rechecks my work even if that means getting some second opinions on it here... Thanks

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