Sometimes when it's really cold, say -5 C and colder, my Oslo can't be shut down to my satisfaction so I decided to try and build a secondary air control for those times when she's running a bit too hot even with the primary air fully closed. I have a 6" stainless liner 25' straight up and no option for a key damper because I only have 4" from the back of the stove to the T in a hearth mount installation.
So far it works very well, no down side that I can see and I think it's a better solution than a key damper: on those cold nights when I want to go to bed feeling secure and knowing there will be plenty hot coals in the morning, instead of having a firebox full of primary flames and a stove top temp of 650 or 700, I can now achieve a stove top temp of 500 with nice secondaries and a glowing firebox with occasional primary flames.
I used a piece of black stove pipe to make it, basic tools and very limited metal working skills. Here are some pics:
So far it works very well, no down side that I can see and I think it's a better solution than a key damper: on those cold nights when I want to go to bed feeling secure and knowing there will be plenty hot coals in the morning, instead of having a firebox full of primary flames and a stove top temp of 650 or 700, I can now achieve a stove top temp of 500 with nice secondaries and a glowing firebox with occasional primary flames.
I used a piece of black stove pipe to make it, basic tools and very limited metal working skills. Here are some pics: