crawford_1_3_13Ducted forced-air HVAC systems are the most widely used type of heating and cooling in the U.S. today. If your home has a furnace, standard heat pump or central air conditioner, then you have a ducted forced-air system. Knowing a little about how your system works will help you detect problems with your furnace or other equipment and make decisions about additional equipment such as air cleaners and humidifiers.

Basic forced-air system components include:

  • A thermostat – This signals the system to turn on or off based on room temperature.
  • An air handler – An electric heating or cooling system includes an air handler that contains heat exchanger coils that heat or cool air, a blower to move conditioned air into the ductwork, a filter, and other components.
  • A furnace unit – A fuel-burning furnace that uses natural gas, liquid propane or heating oil contains a combustion chamber (burner) to burn fuel, a heat exchanger to extract heat, a blower to move warm air, and a flue or vent to release combustion gases from your home.
  • Ductwork – The typical forced-air system includes both air delivery ductwork to send heated or cooled air into your rooms and return ductwork to bring conditioned air back to the heater or air conditioner. Vents and registers also help supply and direct airflow.

When your system’s thermostat senses the room temperature is below or above the set temperature, it signals the furnace or air handler to turn on. The blower fan draws room air through the return ductwork into the air handler or the furnace’s heat exchanger.

Next, depending on the type of system, either the furnace’s burners or the air handler’s electric elements turn on, or the heat pump starts up. When the air has warmed or cooled sufficiently, the blower fan pushes it into the delivery ductwork where it flows out to your rooms.

Naturally, there’s a bit more to a forced-air system than that, so if you need help understanding yours, contact us at Crawford Services. We provide the Dallas-Fort Worth area with friendly, reliable HVAC care.

Our goal is to help educate our customers in North Texas about energy and home comfort issues (specific to HVAC systems).

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