The opening on the bottom of the fireplace (called a firebox bottom) operates much like the air intake vents of a furnace.
Because of the design of the firebox and the outer shell, heated air is easily contained and then forced into the room.
A gas insert is a steel encased firebox that is positioned inside of an already designed and usable masonry fireplace.
Once the gas is ignited, the firebox draws in the cold air from the surrounding room and heats it.
If you look within the firebox, you see nice looking logs that serve only as a decorative element.
Non-catalytic combustion stoves create heat right in the firebox, using a baffle for gas flow.
Wood size- Your firebox should be 3 inches bigger than the firewood you put into it.
The air warms between the inner firebox and the surrounding steel shell.
The coiled pipe firebox of the high-pressure hot-water system previously described may be also classed with boilers.
Baldwin, the founder of the famous Baldwin Locomotive Works in Philadelphia, built his first engine, Old Ironsides, for the Philadelphia, Germantown & Morristown railroad; first tried in November 1832, it was modelled on Stephenson's Planet, and had a single pair of driving wheels at the firebox end and a pair of carrying wheels under the smoke-box.