In paint shop,the ASU system is the equipment to supply clean fresh air to the workshop after temperature regulation,humidity regulation and dust removal.It is a multi-functional and large air volume system.The structure of ASU system in paint shop is as follows:inlet-primary filter-heat recovery unit-gas burner-pre-filter-cold coil-hot coil-humidifying section-rear filter-supply fan.The function of the ASU system is to heat,cooling,humidify,dehumidify and purify the external air according to the changing conditions,and to prepare the amount of fresh air required for the operation process.The new energy saving and environmental protection technologies applied in the ASU system include heat recovery technology,circulating air recovery technology,dry scrubber technology and exhaust air purification device(zeolite wheel adsorption process).