Using Electret Filter on HVAC System for Removal of Indoor Particulate Matters

摘要

The building heating, ventilating air conditioning (HVAC) system is applied to keep indoor air quality (IAQ). Traditionally, the aim of the conventional HAVC system is providing a comfortable environment, not special for removal indoor air pollutants. This study applied the electret in the small-scale Heating, ventilating air conditioning (HVAC) system to remove the particles. Various factors, including the particle size (0.05 to 1.0 μm), the total air change per hour (total ACH) (1.0 and 2.0 hr-1), the fresh ACH (0.18 and 0.36 hr-1), and the relative humidity (RH 30% and RH 70%) were considered to evaluate their effects on the particle decay behavior in the HVAC system with using electret filter. The experimental results showed that the decay constant of the 0.1-μm particles in the small-scale HVAC system without using the electret filter at total ACH of 1.0 (1/hr) and fresh ACH of 0.18(1/hr) was about 0.0036 (1/min). The decay constant of the 0.1-μm particles in the small-scale HVAC system with using the electret filter was 0.0130 (1/min). That indicated that when the electret was applied in the HVAC system, the particle decay constant increased obviously. The decay constants of 0.05-, 0.1-, 0.5-, and 1.0-μm particles were 0.0148, 0.0130, 0.0152, and 0.0160 (1/min). The decay constants of 0.05-, 0.1-, 0.5-, and 1.0-μm particles without electret filter in the system were 0.0043, 0.0036, 0.0033, and 0.0035(1/min). The results also presented that the decay constant (without electret filter) of 0.05-μm particles is the lowest. The experimental data demonstrated that the variation of decay constant by changing total ACH is much larger than that by fresh ACH. The results implied that the decay constant of tested particles decreased with RH increasing.