Home Basics: Air Handler and Condenser

Owning a home can sometimes seem overwhelming, especially if you don’t understand how everything in your house works. For example, did you know that your air conditioning unit has more to it than just that piece that sits outside? You probably have an air handler in your basement or attic. Today, we are going to talk about the different parts of your HVAC system and where you might find them.

                So, lets start with that piece that sits outside of your house, you probably think of it as your “air conditioner”, this is your condenser. A condenser turns certain chemicals from a gas to a liquid by cooling it. This process happens repeatedly in order to cool the home. The condenser (in conjunction with the compressor) primarily works with a substance called refrigerant. The compressor turns that refrigerant, typically Freon, into a liquid. That liquid begins to travel through the condenser coils, and eventually the heat can escape. From this point, the liquid heads to a different part of the air conditioning unit (the evaporator) as a highly pressurized gas that is now cooler.

                The newly cooled air is then pushed throughout your home by your air handler, it is located in the attic, basement or a dedicated closet, and may closely resemble the shape of a gas furnace. Depending on the design of your home, an air handler may be a principal indoor component of your heat pump system. Depending on the season, the circulated air is either cool or hot; your air handler assists in regulating the circulation of indoor air and the temperature of the air in your home that you have set on your thermostat or control system. Your air handler consists of an evaporator coil, blower motor, air filter and the electrical and electronic components required to deliver enhanced levels of indoor comfort.

  • Coil:  The indoor coil or evaporator coil is a crucial component of the refrigeration cycle.
    • When your home requires cool indoor air, the coil is cold and removes humidity as the indoor air passes over it. This makes the conditioned air feel cooler throughout your home.
    • When your home requires warm indoor air, the coil is warm and transfers heat to the air that passes over it. This makes the conditioned air feel warmer throughout your home.
  • Blower Motor: The blower moves the air to the connected ductwork to circulate it into your indoor spaces. The blower motor may be a single speed, multi-speed or variable speed model.
  • Air Supply and Return Plenum Connections: Duct work is connected to your air handler by a plenum to
    • “supply” or deliver the conditioned heated or cooled air to your interior spaces
    • “return” the air to the air handler that needs to be heated or cooled
  • Filter: Before your air conditioned or heated air enters your ductwork, it passes through an air filter. The filter is intended to minimize the number of particulates circulated throughout your home, accumulate in the duct work, and land on the indoor components of your heat pump system.

The air is circulated through your home via ductwork, this involves the air being sucked from throughout the house into the heater/air conditioner, where it is heated or cooled, and pushed back through ducts into the living space. Both intake and output of air is critical to smooth-operating ductwork, not to mention heating, cooling, and indoor air quality.

Now that you know the basics of residential ductwork and air handlers, you can ask questions and speak intelligently with your contractor to be sure that you’re getting the system that’s right for you.