Here Installation details of ceiling suspended air handling unit including , belt guard , supporting channel , insulator detail , spring washer ,They are usually located in the basement, on the roof or on the floors of a building. AHU's will serve a specified area or zone within a building such as the east side, or floors 1 – 10 or perhaps a single purpose such as just the buildings toilets. Therefore, it's very common to find multiple AHU's around a building.inside an AHU we will typically find two sets of filters. The first set is known as the primary filters and we also then have the secondary filters. These both have different functions in an air handling unit. for more details of Installation details of celling suspended air handling unit download this file.