Air Handling Unit AHU is a piece of machinery used as a part of a heating, ventilation, and air conditioning system to clean and circulate air. The AHU manages additional tasks besides ensuring that the inside is properly ventilated with outside air. The indoor air will be filtered and controlled for quality, and depending on how long the air purification filters are retained, the air will be clean. Air Handling Unit AHU is very easy to install as well as simple to use.