For most home owners, having an air filter in the main return air duct next to the HVAC fan system or separate filters in the numerous return air outlets in the rooms of the house, constitute whole house air filtration. 99% of these filters are general duty filters that are capable of removing very large airborne particles and not adding any static pressure load to the HVAC fans. The compromise here is that you are trading air flow for not so good air filtration.
In 1985, Pure Air Systems introduced a new HEPA based, fan powered air filtration system that would provide a much higher level of removing much smaller airborne particulate including bateria and some viruses. By using a concept called, partial by-pass system, PAS can attach their HEPA units to the return air side of the HVAC ducting system and because the PAS systems have their own fan, they will not impede the performance of the main HVAC blower/motor assembly. In addition, the PAS units also incorporate a prefilter and carbon media filter for removal of odors and gaseous pollutants.
Since the inception of the partial by-pass concept, PAS has sold thousands of these units to home owners across North America and has even placed some on board ships and in the hospitality industry. This concept is easy to install and can be retrofitted on existing, ducted HVAC systems in any application.
For more information on this and our complete line of HEPA and Carbon based air filtration systems please go to our website at: http://www.pureairsystems.com or call us on our toll-free number at: 800-869-8025.