1920's Octopus furnace operating

[Uncledaddy1]

Hello fellow coal burners I have a friend has a 1920's coal fired furnace from his house for use in his garage. He has used it many years but is puzzled.
It is a luxaire coal furnace it has on the bottom the ash door, while farther up couple of feet is the fill door. His question
Is the fill door above the ash door has vents or louvers. What and when or how do you use the vents? Thank you

[Sunny Boy]

Welcome UD.

Keep in mind that a wood firebed burns from the top down, and a coal firebed burns from the bottom up.

The damper (vent) in the ash door is called the "primary damper". You use that all the time to control a coal firebed.

The damper in the loading door is called the "secondary damper". It is used right after loading fresh coal into the stove to help burn off the higher amount of volatile vapors that come out of the coal as it is first heated. If the vapors are not burned off, they can collect to explosive levels in the stove. Once the vapors diminish and the blue flames start to appear over the firebed you close that secondary damper or else the cool air coming in above the firebed will reduce the draft strength.

If burning wood, you use the secondary damper all the time as the fire control and none or very little primary damper air feed.

Paul

[Uncledaddy1]

Thank you Paul...Stan