Three-Step HVAC Strategyto Ensure the Safe Return of Building Occupants and Users
Step 
Enhance Indoor Air Quality
With HVAC
System Maintenance
Enhance Indoor Air Quality
- Replace / Upgrade Filters. Consider upgrading to MERV 13 or higher if system design allows and seal edges of filters to limit bypass.
- Evaporator / Condenser Coil Cleanings. Inspect and clean evaporator / condenser coils, as necessary.
- Deep Clean Coils. Chemical cleaning coils is effective when eradicating microbes and odors.
| MERV Rating | Air Filter will trap Air Particles of size 0.03 to 1.0 microns | Air Filter will trap Air Particles of size 1.0 to 3.0 microns | Air Filter will trap Air Particles of size 3 to 10 microns | Filter Type ~ Removes These Particles |
| MERV 1 | <20% | <20% | <20% | Fiberglass & Aluminum ~ Pollen, Dust Mites, Spray Paint, Carpet Fibers |
| MERV 2 | <20% | <20% | <20% | |
| MERV 3 | <20% | <20% | <20% | |
| MERV 4 | <20% | <20% | <20% | |
| MERV 5 | <20% | <20% | 20% – 34% | Disposable Pleated Fibers ~ Mold Spores, Cooking Dusts, Hair Spray, Furniture Polish |
| MERV 6 | <20% | <20% | 35% – 49% | |
| MERV 7 | <20% | <20% | 50% – 69% | |
| MERV 8 | <20% | <20% | 70% – 85% | |
| MERV 9 | <20% | Less than 50% | 85% or Better | Better Home Box Filter ~ Lead Dust, Flour, Auto Fumes, Welding Fumes |
| MERV 10 | <20% | 50% – 64% | 85% or Better | |
| MERV 11 | <20% | 65% – 79% | 85% or Better | |
| MERV 12 | <20% | 80% – 90% | 90% or Better | |
| MERV 13 | Less than 75% | 90% or Better | 90% or Better | Superior Commercial Filters ~ Bacteria, Smoke, Sneezes |
| MERV 14 | 75% – 84% | 90% or Better | 90% or Better | |
| MERV 15 | 85% – 94% | 95% or Better | 95% or Better | |
| MERV 16 | 95% or Better | 95% or Better | 95% or Better | |
| MERV 17 | 99.97% | 99% or Better | 99% or Better | HEPA & ULPA ~ Viruses, Carbon Dust, <.30 pm |
| MERV 18 | 99.97% | 99% or Better | 99% or Better | |
| MERV 19 | 99.99% | 99% or Better | 99% or Better | |
| MERV 20 | 99.99% | 99% or Better | 99% or Better |