Selecting the Correct Air Filter for Your Furnace

In a typical furnace, air is drawn into return ducts, where it’s heated over an exchange. Afterward, the heated air is distributed throughout the home via the ductwork until a comfortable temperature is reached. The same system happens with air conditioning as well, but the process involves cooling instead of heating.

Air filters are placed over the return ducts to prevent dust, dirt, and other contaminants from circulating back inside your home. Installing this filter the wrong way, or even using the incorrect type, greatly affects performance and can even cause damage requiring heating and air conditioning repair.

How do you choose the correct filter, though? Here are a few pointers to help you answer this question.

Minimum Efficiency Reporting Value (MERV)

The Minimum Efficiency Reporting Value or MERV is a rating system used by air conditioning repair and maintenance experts to determine how much air can pass through and how much contaminants are caught by the filter. These ratings range from 1 to 16, with the higher number meaning higher filtration ability.

Note that a higher MERV rating can mean that it traps a high amount of particles often at the expense of airflow. This could cause your furnace to consume more energy to make up for the reduced air coming from the return ducts.

Filter Size and Installation

Most heating and air conditioning repair and maintenance professionals can determine the appropriate size filter for your particular system needs. In general, filter sizes vary by thickness, length, and height, with all measurements in inches. Common sizes range from 14”×25” up to 25”×25”. Refer to an old filter or your system’s manual to find the right size you need.

If you haven’t replaced your filters in a while, clean and vacuum the immediate surroundings of your furnace before attempting a replacement.

Air Conditioning Repair

Using an incorrectly-sized filter can damage the return duct and can even cause leaks within your HVAC system. If you have no experience in basic air conditioning repair, or you’re uncomfortable replacing the filter by yourself, give the professionals at Allison Air Conditioning a call at (951) 356-4224. Our services are available in Corona, CA, and nearby areas.