In a normal split system configuration you will find three key players: an air conditioner or heat pump, a furnace and an evaporator coil. If you are hazy about how these work together to provide cooling and heating, see our HVAC Information page.
So what is an air handler? An air handler is a combination of the evaporator coil and the fan motor from a furnace. Air handlers are used in environments where cooling only is required, or where a heat pump provides both heating and cooling without the assistance of a furnace. They look very similar to a furnace, and sit typically in the exact same place a furnace would.
The photo to the right shows an air handler sitting in the same place a furnace and evaporator coil typically reside.
HVAC Advice: When selecting an air handler or fan coil, remember to get one that has a variable speed fan. Variable speed fans increase efficiency and comfort levels. They also provide better indoor air quality control when using humidifiers and air cleaners.