Sitting in an office, or in their own homes, many people don’t notice their building’s ductwork unless there is something wrong with it — it’s too noisy or the air in the room is too cold or too hot.

If the duct is a standard size, remove the register and drop the fan into the boot. Secure it to the floor on each side with screws. If the duct is smaller than standard, see photos below. Plug the ...

Homeowners know when a duct problem arises. They know when a room is too warm or too cold. But they might misdiagnose the cause. “They are under the assumption that when they get a new a/c system, ...