THE ROLE OF FILTRATION EFFICIENCY IN THE CLEANLINESS OF HVAC SYSTEMS PHASE III

摘要

Since the creation and application of centralized air moving devices in the 1930’s to temper the air in the indoor environment, air filters have been employed. Their role was predominantly to protect the heating element and the related air conveyance system from the potential flammability risk of the accumulation of fibrous lint and particulate matter. As air conditioning became widely used in the latter half of the century, the same air filters took on the additional role of avoidance of fouling of A/C cooling coils. Thus, low efficiency disposable filters have been and are widely employed by HVAC equipment manufacturers of furnaces and air handlers to keep components and systems clean. In the last two decades of the 20~th century, Indoor Air Quality concerns emerged with related attention on particulate contamination and microbial growth in HVAC systems. Thus, system cleanliness has emerged as a critical IAQ and system performance issue. Since little published data existed to provide guidance in selecting appropriate filtration efficiency to attain system cleanliness, a limited field study was undertaken to evaluate the role of filter efficiency in attaining and sustaining clean HVAC systems. rnThe initial screening study included 9 sites within 5 buildings in Atlanta, GA and evaluated installed filtration systems from