1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)

Safe temps for 0" clearance?

Post in 'It's a Gas!' started by pcampbell, Jan 22, 2009.

Thread Status:
Not open for further replies.
  1. pcampbell

    pcampbell Member

    Jan 3, 2008
    I have a DV wall furnace that is listed as 0" clearance to combustibles. I measured the pipe temps today with my infrared gun and found the hottest temps to be around 240F. I am just wondering what is considered the maximum safe range for clearance to framing wood, drywall, etc.

    Helpful Sponsor Ads!

  2. R&D Guy

    R&D Guy New Member

    Apr 25, 2007
    Zero clearance is likely just for the unit, not the pipe. Pipe almost always has clearance required. The install manual should specify this. If its 240° F and touches wood/combustibles then I'm sure its too hot. If it's 240° and there is an air gap then you need to measure the surface temp of the surrounding combustibles.

    ANSI Z21.88a-2007 is the standard fireplaces are certified to today, your furnace is likely a variation of that standard, but Z21.88 says any combustible surface not exposed to the room (not seen e.g. inside the wall) has a maximum temperature limit of 90° F above ambient temperature. So if your house is 70° inside, the combustible cannot exceed 160°. That temperature measurement is taken when the system is at equilibrium (hottest).

    If you are concerned then I don't think there is any reason you can't add extra clearance. I've been guilty of that before.
Thread Status:
Not open for further replies.

Share This Page