When it comes to maintaining your furnace, a clean air filter is the first place to start. Your air filter is designed to filter dust, allergens, and other particles out of the air and trap them. Your furnace system draws air in from the home, through the return air sections of the ductwork. This creates proper air circulation throughout rooms in the home and generates air to flow through the furnace to supply warm or cool air.
When your air filter becomes clogged with various particles, it reduces airflow to the furnace, creating a lack of airflow and causing the furnace to work harder. A dirty filter can also begin to release trapped allergens into the air duct system.
It is important to always use the correct quality and size air filter for your system; in some cases the air filter box may require a non-standard size filter. Although a standard size filter may fit in these boxes, they will leave gaps where dust, debris, allergens, and bacteria can bypass the filter and contaminate the furnace and ductwork. A proper fitting air filter will help extend the life expectancy of your furnace and provide better air quality for your home.
When considering a proper air filter for your furnace system, filter quality plays a large part when it comes to air circulation and reducing dust or allergens in your home. All air filters come with a MERV rating (Minimum Efficiency Reporting Value). The MERV rating was designed in 1987 by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to help evaluate the effectiveness of HVAC air filters. ASHRAE has found that filters with a MERV rating of 7 to 13 are almost as effective as a true HEPA filter in residential applications.
There are two basic styles of air filter: fiberglass and pleated.
Fiberglass filters are usually white or blue and are transparent; these filters have a very low MERV rating (Between 1 and 4) and are best suited for temporary use during renovations or similar situations. A pleated filter captures dust and allergens that a fiberglass filter won’t and carry a much higher MERV value, these filters a best suited for regular use.