HEPA Certification

When shopping for an air filter, one of the best indications of quality you can look for is a HEPA certification. This ensures the filter is made to exacting standards and will do the best job of cleaning the air.

HEPA Filters

HEPA stands for High Efficiency Particulate Air, and a HEPA filter is one designed to trap particles as small as 3 microns in size as well as filter 99.97 percent of these particles out of the air.

HEPA-type

Some filters are advertised as "HEPA-type" filters, and while they may do a good job at cleaning the air, they have not passed the exacting HEPA certification standard.

The Test

One test for HEPA certification involves two stages. First, particles of various sizes are introduced to determine which most easily passes the filter. Then, that size particle is introduced in volume, to determine how many the filter captures.

Conditions

The certification test must be performed under airflow conditions the filter would experience in actual use, to ensure that a HEPA-certified filter performs properly for the end user.

Certification

If the filter allows through no more than 0.03 percent of the test particles, then it may be certified as a HEPA filter.

References

• BestVacuum.com: How To Select A HEPA Air Purifier
• AirPurifiers.com: HEPA Air Purifiers