For many commercial and residential HVAC systems, air filters and/or carbon media adsoprtion media filters, are located on the downstream side of the air handler ( fan ) section. These filters see all of the air from the return air system. Over time, these filters will get very dirty and start to load up and create some additional resistance across the air handler fan. This additional static load will actually reduce the amount of air flow since the higher resistance will create an issue for the fan and motor and thus reduce air flow. This means it will take longer to heat and cool the building structure using more power.

If you are using a high efficiency filter like a HEPA media filter, these filters have an extremely high resistance when clean and the pressure drop across the filters gets very high as the filters load up. In addition, you really need a medium duty air filter ahead of the HEPA filter as the HEPA is really designed to remove very tiny (sub micron ) particles ( think Bacteria and Viruses ). Therefore, putting this combination of high efficiency filters and HEPA filters in line in the air handler is very difficult.

To resolve this issue, Pure Air Systems, uses their fan-powered HEPA based air filtration systems that are incorporated into the return air side of the HVAC system. By taking only a portion of the air from the main return air duct and then putting that back into the air handler upstream of the fan, the PAS units can filter a portion of the air through very highly efficient HEPA filters without affecting the pressure drop across the main air handler fan. While this approach only takes a portion of the return air, over a 24 hour period, this concept will filter all the air in the home or office 24 to 48 times per day. 

For more information on the PAS complete product line please go to our website at: http://www.pureairsystems.com or call us directly at: 800-869-8025.

Post Tags: air filters airborne allergens bacteria bars and restaurants cigarette smoke removal furnace filters HEPA Filters HVAC systems Pure Air Systems Virus whole house air filtration

Post Comments

About the Author: Don Musilli

My name is Don Musilli. I started Pure Air Systems in 1985 and then sold it in 2006. I continue to consult for PAS and write their blog and control their Twitter account. I also, on occasion, make changes to the website. The company is now almost 26 years old and has been a major player in offering commercial grade, high performance HEPA and Carbon based filtration systems for the commercial, institutional, industrial and residential markets.

I currently reside in Englewood, Florida where I write blogs and do social media marketing for a number of clients.

Stay In The Loop

Don't miss out! Like us on Facebook, Follow us on Twitter or subscribe to our RSS Feed and get our latest posts.