Filters seem like a simple component, but when it comes to your furnace they are one of the most important parts that a homeowner has control over.
Purpose of Furnace Filtration
The furnace filter prevents debris from getting into the furnace itself. This debris can come from pet hair and dander, dust, air pollutant particles, pollen, and a host of other microscopic items that are floating in the air at any given time. This filtration is achieved with at least one filter, typically located inside a housing assembly on the side of the main furnace blower unit. Some furnaces have additional filters attached to either the furnace intake or to the main outlet that blows into the ducts.
The reason you want to keep debris out of the furnace is for both the health of the furnace and of your family. Dust and debris inside the furnace can coat moving components so that they work less efficiently. If debris gets into the blower motor, it may break down. Further, debris will recirculate through the furnace and into your home, where it can clog ductworks, lead to a dusty home and the need for more cleaning, and affect your respiratory health.
Poor Filtration Problems
You may not notice that there are filtration problems right away, but over time the issues become obvious. Your furnace will become less efficient, which means your heating costs will go up. Often, you will notice more dust around the house and you may need to clean more often. A burning smell may sometimes accompany the furnace popping on as dust inside the burner or in the ducts heats up or burns off.
Mechanical breakdowns may also increase. Your fan and blower may become noisier as the debris inside the housing affects lubrication and smooth operation. The blower motor may also become prone to overheating and shutting down before a heating cycle completes.
Issues with filtration typically occur for one of two reasons—failure to maintain a clean system or using the wrong filter. Maintaining a clean system means more than changing the main filter on the side of the furnace every month or two. You must also periodically dust or vacuum out the housing itself as debris can fall off the filter when you remove it. Further, the furnace should be serviced and tuned up every year. Your maintenance technician will dust out the blower assembly and fan, as well as make sure everything is properly lubricated.
The second reasons can be handled simply by using the size and rating of filter that is recommended by the furnace manufacturer or your furnace tech. For example, using a higher rated filter than your furnace is made for may seem like a good way to improve filtration, but higher-rated filters may not allow for enough airflow for your furnace to operate effectively.
Contact a heating contractor if you suspect filtration issues are compromising your furnace.