Portable HEPA units have been around since the early 80’s. The majority of the early versions were round, using a doughnut shaped HEPA filter, wrapped with a prefilter/carbon media to capture the larger particles. The blower/motor was inside the HEPA and pulled the dirty air through the HEPA through slots or holes located in the outside of the case and the clean air exited through the bottom.
Most of the early versions had three speed motors so you could adjust the volume of air based upon the size of the room or amount of noise you could tolerate. The air volume movement for the units, as measured in CFM, ranged from 50 CFM to 250 CFM. However two major problems occurred with these units. First, any speed setting above the lowest one created enough noise to make you slit your wrists…twice. Second, the rated air flows never approached the stated CFM volumes from the manufacturers. This meant you had to run the system at its lowest setting if you were in the room and then it would take a very long time to clean all the air in that room. But they were the only game in town.
Subsequent portable HEPA units were not much better. Where the original was made from metal and heavy duty plastics, the newer units, mostly imported from overseas, were all plastic. They were just as noisy as the first units but were less expensive and the replacement filters were cheaper. These units used what was called, faux HEPA filters. They were not certified or designed using any of the certified HEPA filter rating systems but they were still called HEPA units. The public had little choice to purchase these if they want HEPA filtration for their indoor environment.
Pure Air Systems was started in 1985 and from the beginning used only commercial grade, certified, metal framed HEPA filters in their systems. Over the years PAS developed a range of larger units using variable speed, digitally controlled motors that could move from 100 CFM to 2000 CFM of HEPA filtered air. And do it rather quietly. These systems were designed to be attached to existing HVAC systems or be used as stand-alone units.
In 2005 PAS began working on the design for a new portable HEPA unit that would be a commercial grade, powerful and quiet unit with air flow volumes two to three times the levels of the current units on the market. These systems had to be small and light enough to be easily transported and be rugged enough to with stand the abuse of use in commercial and institutional environments. After 16 months of trial and error the HPS 350 and HPS 500 were born. The most powerful and effective true HEPA portable units on the market today.
For more information on the technical specifications you can go here and find out all about the HPS series by Pure Air Systems. You can also follow us on Twitter @pureairsystems or call us on our toll free number at: 800-869-8025.