Filter Applied In Particulate Matter Control In Residental Environment

The purpose of HVAC system is to create not only proper thermal conditions but also good indoor air quality in an occupied zone. One of the major air pollution sources is Particulate matter (PM). PM is a mixture of particles that can adversely effect human health. PM is usually divided up into different classes based on size. In general, the smallest particles pose the highest human health risks. To ensure the air quality in public places, many national codes (GB50019-2003, GB/T18883-2002, etc) have been developed and require that the average value of particles in the indoor air per day should be equal to or less than 0.15mg/m³. This requirement suggests that the application of air conditioning system is switching from comfort-oriented to comfort& purification-oriented, which brings new challenges and opportunities to the control of particles in civil air conditioning systems.A direct and feasible way to remove the particle contaminants is to use filtration devices. However, the air conditioning systems in normal Chinese buildings nowdays only have filter with low efficiency or there is no filter at all. How to design and choose the proper filtration devices is still not well understood.Many studies were therefore carried out, and the following results and conclusions can be drawn from them:The pollution situation in China is studied and existed measurement data such as pollution index, contamination concentration and main pollution source in Shanghai and Shenzhen is collected and analyzed. The particle concentration in both indoor and outdoor air of some public place in shanghai is measured. The sampling items include PM₁0, PM₂.5, PM₁.0. Measurement results shows that about 60% of total weight of PM₁0 is PM2.5 which means filter efficiency for particle below PM2.5 could be highly interested.Two new test apparatus are developed to test different filter materials and filter. Grade filtering efficiency and resistance are measured with different air speed. The influence of particle size, fiber diameter, density of fiber and filter airspeed are also analyzed.According to above tests, electrets filter is recommend for the application in interior building environment.A steady-state model of indoor particle concentration is presented to compare the capability of different filter device.