Simply Sheet Metal recommends air filters (a.k.a. furnace filters) with a MERV 7 - 8 or MPR 600 designation. This MERV (a.k.a. minimum efficiency reporting value) rating or MPR (a.k.a. Microparticle Performance Rating) will collect mold spores, cooking dust, hair spray, furniture polish, pollen, dust mites, spray paint, carpet fibers, cement dust, and pet dander.

We do not recommend using filters with higher ratings as the higher rated filters will cause excess strain on your air handling equipment by introducing more restriction.

Air Filter Replacement Intervals

The typical recommended replacement interval for disposable filters:

• 1” thick filter = 90 days
• 2" thick filter = 120 days
• 4" thick filter = 180 days
• 5” thick filter = 360 days

If you have animals these intervals will be reduced.

*all above intervals are approximate and greatly depend on the environment.

Simply Sheet Metal recommends checking the filter at least once a month to ensure maximum efficiency of the air handling system.