Home Furnace Components

Almost all home furnaces are controlled by a wall thermostat.

People might not think too much about the furnace that's included when they purchase their home. That changes once a furnace has problems or needs repair or servicing. While there are a variety of furnace types and installation modes, some basic components are common to all systems.

Power Supply

The heat from a furnace can be supplied by gas, oil or electricity and sometimes a combination of two of these elements. This allows for a variety of installation choices and can often help reduce overall energy costs. Furnaces typically come with an AFUE (Annual Fuel Utilization Efficiency) rating, which indicates the overall efficiency and performance of the furnace, and the higher the AFUE rating, the lower the fuel costs.

Fan

A furnace comes equipped with a fan to help distribute the heated air throughout the system. Many furnaces have a variable-capacity system that operates on demand, reducing overall costs and energy usage. For the most efficient air distribution, clean the furnace air filter on a regular basis and keep the furnace vents, grilles and return registers clear of obstruction.

Filter

Most furnaces have an air filter installed, usually on the side or just inside the front access panel. This filter helps clean the air brought into the furnace before the air is heated and distributed through the home. A filter can help improve the overall air quality in the home and can also be an important part of the furnace's overall functioning. Disposable and permanent furnace filters are available at most home retail or hardware stores.

Thermostat

Almost all furnaces are controlled by a thermostat, usually located in a central, easy-to-access place. This thermostat allows users to control whether the furnace is on or off, whether it is set to run constantly or only as needed, and the temperature at which the furnace should operate to warm the air. Many thermostats (and furnaces) are also combined with a whole home humidifier or air conditioner and control these units as well.

References

• Lennox: Furnace Brochure
• American Standard: Furnaces
• Bryant: Furnaces for Split Systems