The filters on your system can be upgraded to filter out smaller particles to lower the contaminant concentrations.

Viruses, in particular, can be 1/400th the thickness of a human hair and require extremely fine filters to catch them effectively. HEPA filters (used in surgical operating rooms) would be required to achieve effectiveness of 99%+ capture rate at 0.3-micron size range. These filters are very expensive (initial cost and replacement costs), and unfortunately place a very large strain on the performance of the equipment. Standard commercial HVAC equipment is designed to operate like “drinking a soda through a standard straw”; but changing to HEPAs would be the equivalent of “changing that straw to a coffee straw”. The amount of air flowing through the filter will be drastically reduced, which can lead to temperature issues, maintenance issues, operation issues, and increased utility costs. Contact us to discuss what level of filtration is right for your system to best clean your air without putting your equipment at risk.

wdt_ID MERV Rating Capture Percentage Micron Size
1 1-4 20% 10+ Microns
2 5 20-35% 3-10 Microns
3 6 35-50% 3-10 Microns
4 7 50-70% 3-10 Microns
5 8 70% 3-10 Microns
6 9 Up to 50% 1-3 Microns
7 10 50-65% 1-3 Microns
8 11 65-80% 1-3 Microns
9 12 80% 1-3 Microns
10 13 Up to 75% 0.3-1 Microns


TOTAL Mechanical is Southeastern Wisconsin’s premier commercial, industrial and residential HVAC, electrical, plumbing and fire protection contractor.

Call Us: 262-523-2500