(689a) Performance and Costs of Multi-Element Structured Arrays in Air Filtration

According to the US Department of Energy, the Heating Ventilation and Air Conditioning system (HVAC) accounts for 40 to 60% of the energy used in US commercial and residential buildings. With society becoming more aware of the effects of energy consumption, HVAC efficiency starts to come into notice. The simplest way to improve energy efficiency in a HVAC system is to reduce the pressure drop over the filters. In addition, the demand for improved air filtration due to poor indoor air quality (IAQ), potential threat of biological outbreaks, and increasing control standards in industrial applications has created a need for medium efficiency particulate air filters combined with a gas phase sorbent/catalyst scrubber. Microfibrous-supported sorbent materials (MSSM) engineered at Auburn University excel at removing particulate matters and harmful airborne contaminants such as formaldehyde, and volatile organic compounds (VOC's) that are commonly cited to cause and aggravate asthma, allergic reaction, cancer and other respiratory diseases. However, these dual-functioning materials have substantially higher flow resistances than traditional filtration media due to the decreased fiber diameters, tighter packing densities, and presence of adsorbent/catalyst particles. The utilization of these filters results in a significantly higher energy consumption; thus, these materials are limited in their use as media for air filters. Pleated filter design is a common approach in the air filtration industry to increase the available media area and reduce the pressure drop. Multi-Element Structured Arrays (MESA's) represent a new approach that expands on the pleated filter's premise. By integrating multiple pleated filter elements into a single filtration unit, MESA's can further increase the available filtration area and reduce pressure drop across the system. Current research is focusing on testing the filtration performance (initial pressure drop, removal efficiency, and dirt loading capacity) for different MESA units. The experimental results show that a MESA unit can reduce the initial pressure drop by 75%, hold more than five times dirt and provide better particulate removal efficiency comparing to the same single pleated filter used. The effects of fairing, pleat alignment, filter depth and unit number on the filtration performance will be studied. Based on the measurements, estimations for the useful lifetime and the average energy consumption of MESA units were made. It was found that a MESA filter unit could be utilized to provide equal or superior particulate removal efficiency while operating at only 23% of the power of the traditional pleated filter. Full cost of MESA's was further modeled based on the information collected from our testing beds. Therefore, MESA architectures show great potential for energy efficiency in air filtration while improving indoor air quality.