A true HEPA Vacuum must have a HEPA filter correctly sized for the air-flow rate (CFM) of the vacuum. Pullman-Holt HEPA filters contain the appropriate amount of HEPA media to match the CFM of the vacuum. At first glance, Pullman-Holt HEPA filters seem much larger than what you might expect. Our HEPA filters are oversized, using more filter media to slow the airflow. This causes the particles in the airflow to slow, increasing the dwell time of the particle inside the filter, and the likelihood of the particle being intercepted or captured by the filter. You will also see longer HEPA filter life, and increased performance due to the extra filter media.

Your only assurance that a vacuum has a proper HEPA filter is to be sure it conforms to the Institute of Environmental Sciences and Technology (IEST) recommended procedures and practices for determining whether or not a filter meets true HEPA standards. Each Pullman-Holt HEPA filter is tested, assigned an individual serial number, and certified in accordance with IEST-RP-CC001 test requirements providing a minimum efficiency of 99.97% at .3 micron. Many other manufacturers filters are not individually tested. Some manufacturers will test one filter and assume all of the others made after it will perform to the same level of efficiency. This is not always true. Not testing each filter means hidden holes or weaknesses in the filter media will go unnoticed. Missing or incomplete glue joints can leak, gaskets can leak, or a myriad of other factors can converge to cause a new filter to leak. If you do not see a IEST testing label with an individual serial number on your HEPA filter, then you probably have a HEPA filter that was tested at a much slower rate of airflow than the operating airflow of your vacuum, or one that was only batch tested.

Each filter is individually tested and certified to provide a minimum efficiency of 99.97% at .3 microns, in accordance with IEST-RP-CC001 test requirements.

Air Seal Gasket - Provides a tight air seal and prevents leakage

HEPA Media - The filter is made from a single piece of high-grade HEPA media to eliminate the possibility of leaks. The pleats in the media are held open by corrugated aluminum separators for maximum airflow.

Spacer Sleeve - The purpose of the spacer sleeve is to space the Dacron bag away from the HEPA filter body so as to utilize the full area of the "Never Clog" Dacron bag.

Polyester Prefilter - This impact filter is about one inch thick and is attached to the inlet (bottom) surface of each HEPA filter. Its function is to provide final protection to the HEPA filter from premature failure due to clogging.

"Never Clog" Filter Bag - Sheds dirt and debris like a duck sheds water. Shakes clean to maintain maximum airflow.