We live in an old house. Before the 1960s, there were two wood stoves on the first floor that heated the whole house. Each had a stove pipe that passed through a second story bedroom and continued up through the roof. Those stove pipes heated the second story.
We sell antique cast iron floor registers to other old house dwellers. Floor registers control the flow of warm air from a duct system or just from one story to the next. Most can be opened or closed like the vents in your car.
