Clearance to combustibles? Picture.

[DMoore]

I recently installed a Metalbestos chimney and a Brunco 150 wood furnace. Of course the insurance company wanted be to have it inspected by a pro since I did the work myself. I had that done Saturday and the chimney was fine. The inspector wanted me to change a few things for my inside hook up. What threw me was he said I had to have 36" of clearance to combustibles from my black stovepipe to the ceiling. Now, Brunco's website ((broken link removed)) calls for 12" of vertical flue clearance and 18" horizontal clearance. Not really a problem, he wanted me to make a heat shield to put over the top of the pipe. Here is a picture of what I did... I made 2 heat shields out of 8" pipe, where the inspector said 1 would be enough. I also installed some metal shingles on my floor joists and left an inch of air space there too. The inspector said that every shield with 1" of air space would cut the clearance requirements in half. I had 13" between the pipe and ceiling, installed 3 shields, so that should get me down to 4.5 inches. I just wanted to go a little further than what the inspector said to do, that way the insurance people would be happy. The insurance guy is coming this afternoon, I hope he accepts it. I'm actually burning wood for the past day because the fan on my electric furnace burned up a few days ago. What do you think? Is 36" correct for the clearances or should I go by what the stove manufacture suggests?

 

[DMoore]

The two curves shieds are hanging. I suppose they could sway if I bumped them with something, but no more than an inch to the side because they would hit the pipe. It does not sway during normal operation. The wire I used to suspend it is kind of stiff and does allow it to move much. The shield on the floor joists is secure.

 

[DMoore]

Anyone know if the Brunco is UL listed? I had read that the NFPA coded are for those appliances that are not UL listed.

 

[begreen]

I'd like to see the shields attached with rigid brackets. They could be made out of flat stock or even 1" aluminum angle stock. If using angle stock, cut the last 1" an fold it over to make a mounting tab. Also, is each section of flue screwed together at 3 equally space locations around the pipe?

 

[Nofossil]

From a technical (if not legal / code) point of view I have to think that's more than adequate.

Point of interest for anyone doing heat shields: Shiny surfaces such as polished stainless, aluminum, copper, or galvanizing are VASTLY more effective than flat black. Not only does the hot side reflect almost all the heat (rather than absorbing it), any heat that is absorbed or convected to the shield is not radiated effectively at all from the other side.

 

[DMoore]

Well, it passed the insurance guy's inspection, so I'm good to go. I did find where this unit is UL listed as well. Just in the nick of time too, because my fan on my electric furnace gave out a few days ago. I grew up with this unit, so I know how to run it pretty effectively. It is a toasty 76 in my basement and 72 upstairs, but it's only 40 outside. I've got a guy coming in a few days to hook it into my duct lines.