October 19, 2014 @ 8:45 PM

Triple Wall Chimney


We often get calls from customers looking to replace or add to their existing double or triple wall factory built chimney pipe. These products do not mix and match. Each manufacturer has it's own engineers and patents for their product who design the chimneys, and they are not universal (possibly on purpose). You really need to find the manufacturer and model and try to find a dealer or use a "Google" search to locate similar parts if they are uncommon.

We also hear a lot of someone trying to use a double or triple wall chimney product they have in their possession to hook up a wood stove. Any chimney pipe to be used for an actual wood stove needs to have insulation around the inner most wall to be proper and safe. If chimney pipe was originally designed for an open "pre-fabricated" or "zero clearance" fireplace it is dangerous to use foe a wood stove. The reason is the original appliance it was intended to be used with, in this case an open fireplace, is much less efficient. This means it puts most of it's heat up the chimney keeping it hot and gets as much air as it needs to burn more completely due to the open design. The air space around the inner wall of the chimney actually allows air-flow and convection between the layers to help keep the chimney and the appliance below from overheating.

When you burn an efficient style wood stove both of these variables are reversed. A wood stove puts most of it's heat out into the room and therefore the chimney stays cool. The air space around the inner wall of an un-insulated chimney then allows the inner wall to be cooled even further. This coupled with the fact that you "damper" the air intake to the stove back for a long efficient burn time means there is much more particulate in the smoke that is left unburned. Even in a catalytic or high efficient stove. This particulate coupled with the low chimney temperatures cause an insulated chimney to become a creosote generating machine and a real danger for chimney fires.

"Metalbestos" is one of the only brands of "Class A" or type HT (high temperature) insulated chimney that has kept it's compatibility with it's predecessors. The new product is designated "UT" (Ultra-Temp) and is backwards compatible with the older Metalbestos models "SS" & "SS-II".