A small air handler unit is a type of heating, ventilation, and air conditioning (HVAC) system that is designed to provide air conditioning and/or heating to a specific area or room. It is typically used in residential and commercial buildings and is typically much smaller than the central air conditioning system. Small air handler units are usually installed in the ceiling or in a closet and are powered by electricity. They are typically used to provide cooling and/or heating to a single room or area, and are often used in conjunction with a central air conditioning system. The main benefit of a small air handler unit is that it is more energy efficient than a central air conditioning system, as it does not require as much energy to operate. Additionally, small air handler units are often quieter than central air conditioning systems, making them ideal for areas where noise is a concern.