I need to run a 120V receptacle circuit and a 3/4" stub up for low voltage down a chimney space. They (the owner) say the chimney is built with double wall flue with 8-10" airspace, and then then the two courses of brick. I have no idea what the ambient temp would be in this chase. Sounds easy enough. Has anyone here ever done this? I have seen receptacles on masonary hearths but they were all new construction, never old work.
Thanks in advance.
[This message has been edited by Old Town (edited 12-20-2005).]
I don't think you have enough information to make an informed decision. If there is no draft stopping and ambient air can follow the conduit up the chimney space I would not expect much temperature rise but if this is only open at the top your mileage will vary, based on how much makeup air could displace the hot air that exits. It may not get hot enough to support combustion but you have to start derating at 86f/30c. At a combined temp (ambient plus I2R heating) of 90c/194f your THHN insulation may start failing.
#59994 - 12/20/0508:00 PMRe: Inside A Chimney Chase
I removed a brick above the mantle and I found this: Behind the brick , a 2 1/2" space between the brick and sheetrock. Behind the sheetrock is an additional 8" and then a double flue setup. I can easily run flex behind the brick. What do y'all think. Thanks in advance.
#59997 - 12/21/0501:45 AMRe: Inside A Chimney Chase