Less Smoke at Startup Closing Damper

[mnowaczyk]

I'm still a noob, and think learned something simple. I never wanted to close the damper/bypass with the doors open (before reading the manual) for fear of smoke coming in the house. After I got over this, learning that a good draft is all I need, I just started keeping the bypass closed much more. I found it interesting, by makes sense, that when I am starting a fire, and seeing smoke inside the insert, that it's because it's not hot enough. Close the top bypass, and the smoke stops instantly, and the flames get lazy, looking like a secondary burn.

Does this make sense?

 

[Todd]

Yeah, makes sence. As long as you have good draft smoke should not be an issue. Why is there a bypass damper? Is it an old cat stove?

 

[mnowaczyk]

It's an 1981-82 model non-cat stove. The bypass / damper (which fully closes) is very helpful to get a draft going when first starting a fire, or when opening the doors wide open. With the doors wide open, smoke will often come into the livingroom. The afterburner collects exhaust at the mid-lower back of the stove, and runs it up above the firebox before exhausting just above the closed bypass damper. If the damper is open, exhaust has a striaght shot through a die opening to the flue. when the doors are cracked open, like during startup, to provide more air, the open damper results in less constricted flow, and more airflow. I used to keep the damper/bypass open whenever I opened the doors for fear of smoke coming into the room, but realized I was being a little overly cautios. I knoew the stove would get a little hotter with the damper closed, not letting all the heat right out the top, but it was really cool to see the smoke instantly disappear and secondary flames kick right up when I closed the bypass damper. The stove must have been right at that temperature point where too much cold air was cooling the firebox, and closing the damper / bypass was all it needed to start burning the smoke, of which there was a lot (due to the bark, leaves, paper etc that I was using to get the fire started). Cool lesson learned. Hot, dry, and hotter seem to be the lessons learned again and again with this thick cast fireplace insert.