What is a MERV Air Filtration System?

MERV stands for Minimal Efficiency Reporting Value, a value that measures how effectively a filter stops particulates of varying sizes from passing through and into the air system. The higher the rating, the more effective the filter is at capturing smaller particles. Ratings 1-16 are HVAC use; in general, houses usually have around a MERV 5-12 system. MERV 17-20 are HEPA filters that are used in hospitals and laboratories.

Can I Install a MERV 16 or HEPA Filter Myself?

Homeowners cannot just install a MERV 16 or HEPA filter into their homes. In many circumstances, the HVAC systems homeowners have in place simply aren’t strong enough to handle higher-rated filters, as the more filtration the air has to go through, the more resistance it has to overcome. Even if you were to get a thicker filter that increases surface area, meaning less resistance, you’ll have to check if your HVAC system has enough space to install a thicker filter. Check with an HVAC technician to check what rating your system can handle.

Steps for Building a DIY Air Filter:

If you are unable to acquire a higher rated filter, Ross demonstrates how to build your own DIY air filter. By taking four MERV-13 air filters and duct taping them on all four sides of a box fan, you’ll have a localized air filter for any room you want. For about $150, you can have some peace of mind during wildfires and other disasters that impact our air quality.

Resources:

Ross built the air filter using four, 20x20x2, MERV-13 air filters, which Ross got from Filterbuy. He duct-taped the filters to a cardboard box and a 20-in 3-Speed Box Fan, which is manufactured by Lasko, though any 20” fan would work for this application. Expert assistance with this segment was provided by Neil Comparetto.

Materials:

20-inch box fan Four 20x20x2 MERV-13 air filters Duct tape Cardboard cutout