Your HVAC (Heating, Ventilation and Air Conditioning) system is a major part of your home with a significant expense. Proper care and maintenance will ensure its efficiency and extend its lifespan. Proper regular maintenance by a licensed professional HVAC company is worth the expense, and far beyond the average “handyman.”
The average homeowner can contribute to the “health” of the heating and air conditioning system by replacing the air filter at regular intervals, with the proper type of filter. This will affect the efficiency, condition and lifespan of the evaporator coil, the blower motor and the ducts, and that means saving lots of cash.
The first question concerns how often to replace; this depends on a few variables in your lifestyle. No filter should ever be used for more than 90 days. For a large number of occupants, pets, smokers, and other air quality health issues, the filter should be replaced every 30 days.
Choosing the type of filter also depends on your needs. Is there anyone very young or elderly? Health issues, such as asthma, allergies, COPD? Any pets or smokers? Are you concerned by mold spores, bacteria, germs, viruses?
There is no mandate for labeling air filters with a universal efficiency rating, but most will provide their own. Most well known is MERV (Minimum Efficiency Reporting Value) is determined by the size of particulates captured, dust holding capacity, and pressure drop. A MERV rating ranges from 1 (low efficiency) to 16 (high efficiency). I recommend stay away from filters rated below 5. Filters rated 13 to 16 may create too much pressure drop. Ratings of 8 to 12 is the best choice overall.
Not all manufacturers display a MERV rating, instead using a scale of their own; for instance, Home Depot has their own rating system. Nearly all labels do provide a list of particulates that the filter is designed to capture. Another good feature to look for is “electrostatically charged.”
My best advice is to consult the HVAC pro next time he arrives to “tune up” your heating & cooling equipment. His suggestion will be the most informed of all.