Summary
High-efficiency particulate air filter, or HEPA filters, remove 99.7% of particles .3µm in size. These are very efficient air filters that are typically reserved for HVAC systems in health-care settings where decontamination is essential. Unlike most filters, high efficiency filters can remove droplet nuclei and viruses from circulating air. HEPA filters tend to be much thicker than MERV-rated filters and significantly disrupt air flow, therefore they are only suitable for powerful HVAC systems. The only filter more efficient than HEPA is an ULPA filter, or Ultra-Low Particulate Air. ULPA filters are capable of removing 99.999% of particles with a minimum particle penetration size 0.1 µm such as airborne pathogens.
Filtered Particles
Airborne Pathogens
Viruses
Respiratory Droplets
Bacteria
Fungal Spores
Implementation
HEPA filters designed for HVAC systems are only primarily used in medical settings such as surgery or isolation rooms. Occasionally, they might be recommended for commercial settings that produced large quantities of fumes. While HEPA filters are extremely effective at cleaning the air, they are large and significantly decrease air flow so they require specialized HVAC systems.
Portable HEPA filtration systems are far more accessible for all types of residential and commercial properties. These units are not integrated into HVAC systems. They can be moved between buildings and rooms, and they don’t require any additional retrofitting.
| MERV Rating |
Controlled Contaminants |
Min. Particle Size (μm) |
Application |
| 1-4 |
Pollen, Dust Mites, Sanding Dust, Textile Fibers, Spray Paint Aerosols |
> 10.0 |
Pre-filters, Residential AC Window Units |
| 5-8 |
Mold Spores, Dust Mite Debris, Pet Dander, Cement Dust, Hair Spray, Fabric Protector |
10.0–3.0 |
Better Residential, General Commercial, Final Filters, Industrial or Paint |
| 9-12 |
Legionella, Lead Dust, Auto Emission Particulate, Nebulizer Droplets, Humidifier Dust |
3.0–1.0 |
Superior Residential, Better Commercial, Hospital Labs, |
| 13-16 |
Bacteria, Respiratory Droplets, Cooking Oil, Tobacco Smoke, Insecticide Dust, Face Powders, Paint Pigments, Toner |
1.0–0.3 |
Hospital, General Surgery, Superior Commercial, Smoke Lounges |
| 17-20 (HEPA) |
Some Viruses, Airborne Particles, Radon Progeny |
0.3 (MPPS) |
Clean Rooms, Radioactive Materials, Pharmacuetical Manufactering, Orthopedic Surgery |
Sustainability Implications
HEPA filters tend to last far longer than standard MERV filters, only needing replacement every 1-3 years depending on the concentration of air contaminants. They are crafted from plastics and fiberglass, which are not considered environmentally friendly materials; however, their extended lifespan makes them a comparable option to MERV filters made of paper or cotton. Generally, air filters do not pose a significant threat to the environment.
The cost of filters tends to increase with size and efficiency. HEPA andULPA filters fitted for HVAC systems are not very accessible to the public in terms of cost or availability compared to most air filtration technologies. The cost of a high efficiency HVAC filter ranges from about $100 to $500 plus.
Portable HEPA technology starts at $100 and continuously increases for larger units. The filters for portable air purifiers are about $20 and last about 6months or more depending on the amount of usage.