Barometric control on EFM stoker

My Electric Furnace Man coal stoker has been running well for years and years, acually for decades. A visitor commented that I should have a barometric control on it. It sits in the basement, four feet from a stone foundation and the flu into a two story lined brick chimney. When adjusted right for coal feed and air it burns very well. I heat a two story house with about three tons of coal supplemented by a wood burner on a separate chimney. Do I really need to add a barometric control for my EFM stoker?
Much appreciated,
Fireboy

I think that it allows some air from your room to pass up the chimney instead of being sucked through the stove maybe causing you to burn more fuel than necessary.

Thanks. Very likely true. The stove pipe, however, has never been very warm. Am I correct that any danger of coal gas would be less without the barometric control?

Fireboy

PS: just cleaned the EFM today, ready for another year!