previously described air is pulled into intake fan 49 and may be optionally filtered by a charcoal filter 53 for example located in the inlet path to remove odor efficiently air is also compressed in chamber 39 and applies a positive pressure on filter 43 so that intake fan 49 acts to push air into the system at the same time air is pulled through filter 43 by exhaust fan 35 so there is a dual action on the filter which is provided by two fans from one motor the efficiency of this arrangement is exceptional it is now possible for the first time to provide hepa filtered air at a single workspace without the use of a large motor pushing or pulling air through the filter creating noise and turbulent flow which is sometimes distracting enough to cause the operator to turn off the device instead with the present invention a quiet gentle or laminar flow of air at a moderate velocity extends out over the user to provide virtually a clean room atmosphere in the midst of an otherwise polluted room it has been discovered that motor 45 can deliver the required 150 cfm or more with up to 40 to 60 less current rating specifically it has been discovered that pure air results are achieved with the present invention with a 1 2 amp motor which is fully effective in replacing previously used 2 amp and even 3 amp motors in older designs which did not employ this invention another advantage of the present invention is that it is much quieter than the old single fan methods of filtering with a hepa filter conventional units which attempt to use hepa filters have operated at best at 53 to 57 decibels db the present invention typically.