Can HVAC Air Filters Reduce the Spread of Allergens and Germs?

We’re entering peak allergy season in most states across the U.S., and New York is no different. Unfortunately, the rise of coronavirus (COVID-19) is coinciding with the start of allergy season and the tail end of flu season, and this unhappy coincidence has caused a significant increase in questions and concerns about indoor air quality. 

In the HVAC industry, we’re seeing this question and ones like it surface more and more frequently: can my heating and cooling (HVAC) system’s air filter reduce the spread of allergens and germs? The answer is not 100 percent black and white, but we’ll do our best to “clear the air” with the explanation below.

1. Your air filter does not actively kill microorganisms.

Unlike a UV light system, your HVAC system’s air filter is not designed to eradicate harmful microorganisms (like viruses and bacteria) actively. However, if the filter’s rating is high enough, it can trap things as small as a virus and keep them from entering your HVAC system. If trapped for long enough, a virus can die in your air filter.

2. What your air filter can capture depends on its rating.

The Minimum Efficiency Reporting Value (MERV) rating system is probably the most common, but the rating systems can vary from brand to brand and filter to filter. When dealing with the MERV system, the higher the rating, the smaller the particles the filter should be able to capture.

Here is a basic breakdown of MERV ratings:

  • 1-4: This will help keep dust and other large, airborne particles out of your HVAC system, but it won’t do much for your indoor air quality.

  • 5-13: Aside from dust, filters with these ratings will be able to filter out particles like pet dander, bacteria, viruses, and some mold spores. (Filters with a 9-12 rating can also filter out dust mites and most other indoor allergens.)

  • 14-16: These filters will offer the most protection against indoor allergens and can trap particles as small as 0.3 microns. (As a reference point, the human eye, on average, can’t see particles that are smaller than 50 to 60 microns.)

Keep in mind that you may not want to get a filter with the highest rating because it might not allow an adequate amount of airflow into your HVAC system. Without enough airflow, your system will lose efficiency and can be prone to a number of issues that will involve repairs or replacements. Consult the manufacturer or an HVAC expert about the types of filters your system can handle.

Bottom Line

Your air filter’s most critical task is keeping dust and dirt out of your HVAC system. That being said, with a high enough rating, your HVAC system’s air filter can help trap some germs, allergens, and other indoor air pollutants and prevent them from circulating through your home. However, it will not help against germs and allergens that cling to surfaces, and it will not provide advanced, “whole home” germicidal protection. In short, keeping a tidy, sanitized home remains essential to fighting allergens and staying well.

From everyone at JSP Home Services, we hope you and your family are staying healthy and keeping in good spirits. For 24/7 heating, cooling, electrical, or plumbing emergencies, give us a call at (845) 209-1700 .


Skip to content