Mechanical air filters are found in the duct system of your central air conditioner. Replace or clean them often to properly maintain your A/C.
When purchasing an air filter for your southwest Florida home, you can compare its relative efficiency at removing airborne particles from your air supply using the MERV rating. This minimum efficiency reporting value rating ranges from 1 (low level of efficiency) up to a maximum of 20.
- Flat panel air filters (with MERV ratings 1-4) are often used in residential air conditioning and heating systems. Their purpose is mainly to protect the HVAC equipment from accumulating damaging materials on the internal surfaces. Low-MERV filters aren’t intended to improve indoor air quality and will miss microscopically small particles like viruses and bacteria. They’ll also miss some of the airborne pollen, dust, insect allergens, pet dander and mold spores that are a big concern here in Southwest Florida.
- Extended surface (pleated) filters are rated medium or high on the MERV scale. Medium-efficiency filters (MERV 5-13) are moderately effective at removing potential lung irritants and other airborne particles.
- MERV 7-13 filters are almost as effective as much-higher-rated HEPA (high efficiency particulate air) filters, but much less expensive. Medium-efficiency filters have other advantages; they allow better airflow rates and run more quietly than HEPAs (and other high-efficiency products) because they’re less air resistant.
- Higher-efficiency filters (MERV ratings 14-16), look like true HEPA filters and are sometimes mistakenly called by that name.
- True HEPA filters are rated MERV 17-20, however, and will often overpower home cooling equipment, blocking airflow. So they’re not used often in residential systems, but more often in hospitals and laboratories.
Before purchasing a MERV 14 or above filter, be certain it’s compatible with your cooling system’s fan and motor capacity. Professionally retrofitted residential home comfort systems may be able to accommodate true HEPAs, along with certain high performance houses that might come equipped with a HEPA-compatible system.
Questions about air filters or how to install one in your particular HVAC system? Contact Conditioned Air for expert advice for Southwest Florida homeowners. Please visit our website to learn more or just pick up the phone.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about air filters and other HVAC topics, download our free Home Comfort Resource guide.
Air filter image via Shutterstock