Many home heating and cooling systems move air throughout the home using a forced-air distribution system. A gas furnace, oil furnace, and electric furnace all do this, as does a central air conditioner.  Rather than repeat this information in each of the system guides, let's take a look at how air--no matter how it's made hot or cool--can be distributed efficiently.

How Does It Work?

This forced-air system filter is located on a ledge above the blower. Others are accessed through a narrow door in the blower chamber.

A forced-air distribution system simply picks up air from the heating or cooling source, typically a large furnace or air conditioner, and moves it through the house in large pipes called heating ducts. The return system brings cooler air to the heating device. An encased electric fan, called a blower, moves the air through the system as needed.

What Can Go Wrong?

Thermostats and other controls can malfunction. Filters become dirty and blocked. Blower belts get old and need replacing. Motors burn out.