Exterior chimney efficiency?

[Darl Bundren]

Hey, all. I went stove shopping yesterday and asked a few chimney questions, and I asked the guy how efficient exterior chimneys were. Does anybody here have an exterior chimney of class A without a chase around it? How does that work for you?

Thanks.

 

[jason1238]

Darl,

I have exposed Class A for my outside chimney run, and have had no problems with it, as long as the OAT is below 40°F. Not burning much when it's that warm, but it will reverse draft at that point for some reason. I've had temps down to zero, with wind chills approaching -20 (at which point the stove is cranking!), and haven't seen any problems yet.

My stove is in the basement family room of a bi-level (so it's only half underground!). The Class A comes out of the house about 20" off the ground, and goes straight up 22 feet. It's on the side of the house that faces slightly south west, so it gets all the cold wind out of the north and west.

Mine is Excel brand stainless(made by ICC), and I would recommend it to anyone. It is pricey...a 4 foot piece was around $160, so be prepared to budget accordingly!

There are many other factors that affect draft, though, like surrounding trees, neighboring structures, overall height of the flue, etc. My setup is probably about the worst case, but it works!

Good luck in your search, and I'm sure others will chime in.

-jason

 

[Darl Bundren]

Darl,

I have exposed Class A for my outside chimney run, and have had no problems with it, as long as the OAT is below 40°F. Not burning much when it's that warm, but it will reverse draft at that point for some reason. I've had temps down to zero, with wind chills approaching -20 (at which point the stove is cranking!), and haven't seen any problems yet.

My stove is in the basement family room of a bi-level (so it's only half underground!). The Class A comes out of the house about 20" off the ground, and goes straight up 22 feet. It's on the side of the house that faces slightly south west, so it gets all the cold wind out of the north and west.

Mine is Excel brand stainless(made by ICC), and I would recommend it to anyone. It is pricey...a 4 foot piece was around $160, so be prepared to budget accordingly!

There are many other factors that affect draft, though, like surrounding trees, neighboring structures, overall height of the flue, etc. My setup is probably about the worst case, but it works!

Good luck in your search, and I'm sure others will chime in.

-jason

Jason, thanks for helping me out. It sounds like I am in a similar situation--daylight basement. The pipe would be on the south side of the house, sheltered from our coldest winds and in the sun on nice days, and I am hoping that would keep the chimney temps warm enough to draw on fairly temperate days. I am debating running it outside or inside and wanted more info to help me in my decision. Most of what I've read says that inside is better, but inside may not be our best choice. Thanks again.

 

[jason1238]

Glad I could help!

Yeah, the inside run (as much as possible) is best, but for me it wasn't an option, as it would have put a chimney pipe right up through where my daughter's bed is. I was concerned at first about how it would draw, and had already priced all the material needed for a stick-built chase before I even put the chimney up. Luckily, I haven't had any issues with it.

 

[jtp10181]

I have a customer with a 28' exterior chimney and they have complained about getting smoke back but I have feeling their wood is junk. I was supposed to go out there and replace their griddle top but I never called them back and they never called me. I wonder if its working this year? I should probably call them before it gets warm out again.