HEPA (high efficiency particulate air) filters are designed to remove tiny airborne particles from the air as it passes through the filter. HEPA was originally developed in the 1940s to capture radioactive particles, but today it is used extensively for air purification in homes, offices, hospitals, and more.
The key specification for HEPA filters is the minimum efficiency they achieve at capturing particles 0.3 microns in diameter. To qualify as true HEPA, filters must remove at least 99.97% of particles this size during testing. This article will explore the different types of HEPA filters and their effectiveness at capturing even smaller particles.
Standard HEPA Filters
The most common type of HEPA filter is designed to meet the basic 99.97% efficiency standard. This means it must capture 99.97% of particles sized 0.3 microns during laboratory testing. In real-world conditions, true HEPA filters are highly effective at trapping common airborne particles like:
Dust
Pollen
Mold spores
Bacteria
Pet dander
Smoke
While not tested for particles smaller than 0.3 microns, HEPA filters can still capture many of them at decent efficiencies. Overall, HEPA filters are great for general air cleaning applications where you want to remove airborne allergens and pollutants.
HEPA 13 Filters
The next level up from standard HEPA is HEPA 13 filters. These filters must meet a minimum efficiency of 99.95% when tested with 0.3 micron particles. That may seem like a small difference from standard 99.97% HEPA, but it indicates more filtration media layers that improve performance.
The extra layers in HEPA 13 filters allow them to capture more ultrafine particles below 0.3 microns. This includes things like smoke, emissions from vehicles/factories, and some viruses. Their increased effectiveness makes HEPA 13 filters well-suited for:
Wildfire smoke removal
Industrial sites
Commercial buildings
High traffic areas
HEPA 14 Filters
HEPA 14 air filters are even more efficient at particle removal than HEPA 13 models. They must demonstrate 99.995% minimum efficiency for 0.3 micron particles during laboratory testing.
The extremely high filtration of HEPA 14 filters makes them ideal for hospitals, clean rooms, research labs, and other applications that demand near-perfect air purification. Their increased media layers improve capturing of particles as small as 0.1 microns, including:
Some viruses
Tobacco smoke
Bacteria
Fine dust
HEPA 14 models provide superior removal of airborne microbes, which is critical in medical and pharmaceutical settings.
ULPA Filters
At the top end of air filtration are ULPA or ultra low penetration air filters. While not technically a HEPA filter, ULPA models are even more efficient at removing ultrafine particles.
ULPA filters must demonstrate a minimum of 99.999% efficiency at capturing particles sized between 0.1 to 0.2 microns. This high performance against tiny particles makes ULPA filters ideal for:
Clean rooms
Electronics manufacturing facilities
Pharmaceutical production
Hospitals
ULPA models excel at protecting processes where all airborne contamination must be controlled. They offer superior removal of microscopic particles, though at a higher cost than HEPA filtration.
Finding the Right HEPA Filter
When selecting a HEPA filter, consider the type and amount of contaminants you want to remove from the air. Standard HEPA models work well for general air cleaning applications like homes or offices.
For higher airborne particle loads such as smoke or bacteria, look to HEPA 13 or HEPA 14 rated filters. In extreme environments like clean rooms, ULPA filters provide the best protection against microscopic particles.
Also ensure your HVAC system or air purifier is designed to accommodate HEPA filtration. The dense structure of HEPA filters can restrict airflow compared to other types, so your system must overcome this added resistance.
With their proven ability to capture ultrafine particles, HEPA air filters are an essential tool in creating healthier indoor air quality across many residential, commercial and industrial settings. Source
HEPA 13 Filters
HEPA 13 Filters
