Air cleaners are unitary devices that contain filtration media and fans. They are marketed for cleaning air in rooms. There is no current method for measuring the effectiveness of these devices in rooms of the size where they are typically installed. The proposed method provides engineers and manufacturers with a tool for evaluating and predicting applied air cleaner performance. Test results provide the effective ventilation rate of the device. This rate can be stated in terms of the whole room average, or for specific regions of concern, such as work areas, within the room.
Models are presented for describing the performance of room air cleaners in removing pollutants from indoor air, particularly the levels of removal that can be achieved in practice. Controlled levels of pollutant were generated in a room environmental chamber, and the performance of a commercial room air cleaner was assessed according to the models. The room environmental chamber was operated in static (sealed) or dynamic (ventilated) modes.
Snow has already been used effectively as a cold energy resource in some heavy snowfall areasin Japan. As the surface of snow is covered with cold melting water when snow is used as a coldenergy resource, we can expect gas absorption on the surface. By this mechanism of the gasabsorption, some airborne contaminants such as dust or harmful gases can be removed by themelting snow surface.
The primary objective of this study was to evaluate the effectiveness of different commercially available portable indoor air cleaning technologies in removing dust particulates from the indoor air. Suspended respirable particles are of great concern and often identified as important source of indoor air quality problems. The concentrations of particulate and gaseous pollutants encountered in the indoor environment frequently exceed those found outdoors by factor ranging from 2 to 20.
People who suffer from airborne respiratory allergies often advised to obtain and rely upon portable HEPA filtered air devices for relief. While this advice may work for some individuals, many allergic people do not experience relief or a lessening of symptoms. For allergic individuals for whom this mitigation strategy is not successful, the manufacturers' claims seem over stated.