These heavy duty units are designed for use with Ducted air system. They may also be used with an accessory plenum and grill for free flow applications. The units are equipped with quiet, large volume air movement forward curved fans with large outlet areas to minimize air movement noise. This type air conditioners hidden in the ceiling, this product range is ideally suited for open office areas, large conference room, show rooms, marriage halls and other places where along with cooling efficiency, distributed air flow is essential. Its ranges are 3.0, 4.0, 5.5, 7.5, 8.5, 11.0, and 17.0TR.