Our Experts Explain How Your HVAC Air Filter Works

Your air conditioner’s filter is important for enhancing home comfort and indoor air quality, and for the efficiency of your system.

But choosing the right filter can be tricky. If you’re confused by the variety of filters on the market, use MERV to choose the best filter for your home.

MERV (Minimum Efficiency Reporting Value) is based on a ratings scale of 1 to 16, with 16 as the most effective at removing airborne contaminants. Air filters rated MERV 1 to 4 are generally not recommended. These types of filters do little more than prevent the largest particles from collecting on your air conditioner. If you have one installed in your existing A/C, you would be wise to upgrade, as a higher-rated filter will offer better performance.

Here’s what you need to know:

Air filters rated MERV 5 to 7 are a good improvement, with filtering properties capable of removing tiny dust mite debris, pet dander, mold spores and hair spray. With these filters, you should breathe easier, and have fewer dusting chores.
Air filters rated MERV 8 to 13 are excellent choices for most households. Filters in this range are recommended by the U.S. Environmental Protection Agency (EPA), and for good reason: The EPA states that more than 7 of 10 homes contain higher-than-normal levels of dangerous gases and chemicals, such as auto emissions. If you have an attached garage, you should consider choosing a filter in this range. However, higher-efficiency filters can impede airflow to some degree. The higher the rating of the filter you choose, the more airflow will be impeded for your HVAC system. This increases energy costs and hinders performance. An inspection by a heating and cooling pro is advisable.
Air filters rated MERV 14 to 16 are superior in their ability to capture contaminants. However, these filters significantly impede airflow, possibly to the point of damage in systems ill-equipped to handle the hindrance. Again, an inspection is absolutely advisable for these filters, and likely necessary for fit.

Using MERV ratings to choose your air conditioner’s filter is a simple means to improve the quality of your home life. For more information, contact T.F. O’Brien Cooling & Heating. We’ve proudly served the Long Island area since 1934.

Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Resource guide.