Air Conditioning Filters: MERV Matters
Today’s tightly sealed homes make it easier and more affordable to maintain comfortable temperatures indoors but can cause problems when it comes to indoor air quality. In most homes in Middleburg, FL, indoor air is typically many times more polluted than the air outside. Prolonged exposure to indoor pollutants poses real health hazards, particularly for those who suffer from allergies, asthma and other respiratory conditions. Fortunately, those heating and cooling systems that benefit so much from a tight building envelope are also your first defense against indoor air pollution. Equipping them with the right air filter lets everyone breathe a little easier.
Meet MERV: An Introduction to Air Filter Ratings
Ratings for heating and air conditioning filters are based on the Minimum Efficiency Reporting Value (MERV) scale. This industry scale is used to measure a filter’s efficacy at filtering out particles from 0.3 to 10 microns in size. The smaller the particle, the more irritating the pollutant is to lung tissue. MERV ratings range from 1 to 20. The higher the number, the more effective the product is at filtering pollutants from the air.
Standard Panel Filters
Most HVAC systems come with a flat fiberglass filter with a MERV of 1 to 4. These inexpensive filters are actually designed to protect the equipment from a build-up of dust rather than filter the air. Panel filters can sift out particles larger than 10 microns in size such as mold spores and pollen. To be effective, however, they need to be changed frequently. Pleated filters with a MERV of 5 to 8 do a slightly better job, removing particulates larger than 3 microns, including some types of bacteria.
With MERV ratings that range from 7 to 13, whole-house media filters are HVAC add-ons that can filter out particulates as small as a single micron. Carrier’s Comfort EZ Flex Cabinet Air Filter, for example, is a MERV 10 product featuring deeply pleated folds of filtration media assembled in a box-like unit that fits into the ductwork of your central HVAC system. A MERV 13 filter is also available for this home filtration system.
Which Filter Is Right for You?
Selecting the filter with the highest MERV number isn’t always the right choice. The fans and motors in many air conditioners and heaters simply aren’t powerful enough to accommodate dense filtration systems. The wrong filter can impair air flow and force your heating and cooling systems to run longer to reach desired temperatures. The HVAC experts at Mike Merritt Heating & Air Conditioning can inspect your system to determine the filter best for you.
At Mike Merritt, we also offer services like EPA-approved Home Performance Evaluations that can help identify sources of indoor air pollution and recommend cost-effective solutions. Whether you need help choosing the right air filter or a whole-home air purifier, our goal is to make your home a healthier, safer and more comfortable environment for you and your family.