How to Change Your Furnace Filters: Reduce Repairs and Maintain Furnace Efficiency

As part of your heating system’s annual maintenance routine, a filter change is a quick, simple way to keep your furnace running efficiently and reliably. While many furnace components will require service by an HVAC expert, changing your furnace filters is an easy task you can do yourself.

Furnace filters are made of different types of material, ranging from inexpensive spun fiberglass threads or foam to high-quality, high-efficiency pleated cloth. Filters carry an efficiency rating, the Minimum Efficiency Reporting Value (MERV), an indicator of how well the filter captures particles from 0.3 to 10 microns in size. Home-use MERV numbers range from 1 to 16; higher MERV numbers mean a more efficient filter. HEPA (High Efficiency Particulate Air) filters, with MERV ratings of 17 to 20, provide even higher levels of filtration efficiency, though they're usually not recommended for use in a conventional home heating system.

Furnace filters are usually found in a slot inside the furnace. Open the front access door on your furnace and look for a large rectangular box, probably around an inch or so thick, placed within the path of the air flow in your heating unit. Slide the filter out of the slot and inspect it carefully. Most likely, your filter will show large spots of dirt and debris that have been captured from the air flowing through the furnace. Replace the filter with one of the same size as the one you take out.

Change or clean the unit's filters at least every three months. A monthly filter change is recommended during the winter months. If needed, you can install an air filter change indicator. This gauge detects drops in system pressure caused by dirt accumulating in the filter. When the pressure reaches a pre-set level, the indicator arrow shows you it’s time to change the filter.

Since 1976, Comfort Services has provided residential and commercial heating and air conditioning services to customers in Columbia and the surrounding area. Contact us today for more information on changing your furnace filters and for help with finding the best type of filter for your air quality needs.