Types of HVAC Filters Explained

Have you noticed that you or your children seem to be prone to respiratory infections while at home? The problem may not be seasonal allergies as much as your HVAC (heating, ventilation, and air conditioning) filter. Ultimately, if your air filter is not cleaning the air as it should, you could be breathing in dirt and bacteria, which can make your family sick. There are several different types of filters used with your air conditioner or heater, and each type has its strengths and weaknesses. Here are a few that you may be using and some suggestions on which to switch to.

In order to choose a good filter, it is important to understand the MERV ratings. MERV stands for Minimum Efficiency Reporting Value, and rates how efficient filters can remove particles of dirt, bacteria, and other things from the air. The scale ranges from 1-16, with 1 being the lowest value, blocking larger items like pollen, carpet fibers, and dust mites. A MERV rating of 16 is an extremely efficient filter that will block droplets of water, tobacco smoke, and bacteria. 


Fiberglass filters are usually blue and about one inch thick. These filters are made up of thin strands of glass and need to be replaced about once a month. They are the most rudimentary filters with a MERV rating anywhere from 1-4. 

HEPA Filters

HEPA or High-Efficiency Particulate Air Filters, are one of the best ways to screen contaminates from the air in your home. These filters can screen up to 99.97% of contaminants from air which makes them ideal for people who struggle with asthma, allergies, or other breathing diseases. HEPA filters have a MERV rating anywhere from 12-16.

Electrostatic Air Filters

Electrostatic air filters use a charge to help purify the air in your home. This is done by magnetically pulling in dust and other particles and trapping them in the filter. For the most part, these filters are washable and can be reused. Electrostatic air filters usually have a MERV rating from 10-16.

In conclusion, if you or other members of your family have asthma, allergies, or other breathing problems, you may want to upgrade the type of filter you are using in your home. Most HVAC filters are relatively cheap, and some can even be reused. If you are unsure which type would be best for your family, discuss your situation with an HVAC professional.