ABSTRACT
Air-handling units is the general term for several types air-treating and delivery systems, each of which consists of one or more supply fans, cooling and/or heating coils, air filters, and so on, all contained within a common enclosure or “casing” and factory-assembled. Particulate air filters are applied in air-handling systems to remove impurities such as dust, pollen, and smoke from the air. Dilution ventilation is a process by which some percentage of “dirty” indoor air is continuously replaced by “clean” outdoor air to control odors and reduce pollutant concentrations. For modular air-handling units, it is necessary for the designer to select each individual section and component of the air handler: preheat coil, filter(s), heating coil, cooling coil, fan, type and location of dampers, and so on, so that a complete unit is defined for the manufacturer.
