The furnace is the primary heating source of a central air system. Keeping the furnace well maintained will prolong its life, improve energy efficiency, and reduce the chances of a safety hazard. Every fall schedule a service professional to complete a full maintenance checklist. Although it is possible for savvy DIY homeowners to tackle this checklist, it is best handled by professionals with the proper equipment.
The heating process in the furnace is a combination of combustion and heat transfer. The process starts with the intake of a fuel (eg natural gas) and air. The combination is ignited by the burner and drawn into the heat exchanger by negative pressure from the draft inducer. Air from the house is pushed passed the heat exchanger. The air from the house absorbs energy from the heat exchanger and cools the combustion gases. The air then returns to the living spaces of the house through the duct work. The combustion gases are expelled through the flue to the outside.
One of the most important aspects of routine furnace maintenance is keeping the unit clean by changing the air filter. For most modern homes the filter is located at the air intakes. For older homes a lot of times the air filter is located just before the furnace.
Changing the air filter is one of the easiest ways to keep the furnace clean and operating efficiently. Filters that are too dirty will clog up the air intake and force the furnace to work harder. Using a cheap filter will not capture all dirt and dust particles. Dust collecting on the heat exchanger creates an unwanted layer of insulation.
Every fall a professional maintenance servicing should be scheduled. They have special tools and meters that help to clean up all components and optimize performance. Here are the normal steps for furnace maintenance:
Replace disposable air filters every 2-3 months. For households will pets consider pet specific filters and replacing the filters every 1-2 months. Reusable filters should be cleaned monthly. Check the manual for the filter to see if you can use a detergent or other cleaning solutions. While cleaning or replacing the air filter clean the edges of the air intake.