You vacuum, sweep, dust, and even give your pet a bath!  But your clean air filter still becomes covered with “stuff” that has been floating around in your house. Your filters reveal a dirty little secret - your home and the air you breathe aren’t as clean as you may think!

Replacing a dirty, clogged filter with a clean one can lower your air conditioner's energy consumption by 5% to 15%.¹

Different types of filters are made to capture different types of particulates floating around inside your home. “Particulates” is the fancy word for the dirty “stuff” found in your filter.  According to the Environmental Protection Agency (EPA), a basic low MERV mechanical filter may capture some of your home’s:

• Dust
• Pollen
• Mold spores
• Animal dander
• Larger particles that contain dust mite and cockroach allergens

But the EPA also says that basic mechanical air filters may not be very good at completely removing these particulates because they quickly settle on surfaces.² However, filters can block enough particles and prevent them from landing on fan motors and heating or cooling coils. This protects your HVAC equipment.
 

What’s MERV got to do with it?

MERV is not the guy you met at the gym. MERV is number value that distinguishes the filtration ability of air filters installed in the HVAC ductwork. The MERV numbering system can range from 1 to 20. The higher the MERV number, the better the filter may be at trapping particulates. This means that fewer particles and airborne contaminants can pass through a high MERV filter to your HVAC equipment. 

Residential furnaces and air conditioners commonly use 1 to 4 MERV rated filters. They may not be as efficient in filtering out smaller particles. However, these filters may stop some larger particles from passing through to the HVAC equipment. 

If the MERV rating if higher, there is a better chance of trapping “viruses, bacteria, some mold spores, a significant fraction of cat and dog allergens, and a small portion of dust mite allergens.”³

The EPA suggests that filters with a MERV rating between 7 and 13 can be nearly as effective as true HEPA filters. However, some residential HVAC systems may not have enough fan or motor capacity to accommodate higher efficiency filters. Therefore, talk with your technician about your HVAC manufacturer’s recommended filter type before upgrading to higher MERV filters. Installing true HEPA filters in an existing home HVAC system typically requires professional modification of the system. 

HEPA Filters

HEPA stands for High-Efficiency Particulate Arrestance. These highest rated MERV filters, those with a 17-20 MERV rating, are typically used for “clean” or sterile rooms and pharmaceutical manufacturing. These often require specific HVAC configurations.

How Can I Get Cleaner Air?

Cleaner indoor air is achievable! Licensed or professional HVAC dealers can install whole-home filtration and purification solutions that secretly and automatically treat the air in your home. These systems are meant to purify and deodorize your indoor air, as well as protect and maintain central heating and cooling system efficiency. 
If you are concerned with indoor pollutants, discuss possible solutions and products with your licensed or professional HVAC dealer. 



This article was included in the 2017 Fall/Winter Good Life Magazine.

1 Maintaining your Air Conditioner. (n.d.). Retrieved from Energy.gov: www.energy.gov/energysaver/maintaining-your-air-conditioner
2 Guide to Indoor Air Cleaners in the Home. (2014, July). Retrieved from EPA: www.epa.gov/sites/production/files/2014-07/documents/aircleaners.pdf
3 Indoor Air Quality (IAQ). (n.d.). Retrieved from EPA: www.epa.gov/indoor-air-quality-iaq/residential-air-cleaners-second-edition-summary-available-information#summary