An air handling unit, is a piece of machinery used as a part of a heating, ventilation, and air conditioning system to clean and circulate air. The ahu and its surrounds were revered by the people as hallowed land. The Moai guarded and kept an eye on the residents from the back of this holy area, which they fronted. The air handling unit is a substantial metal box that includes separate ventilators for supply and exhaust, a heating and cooling recovery system, air filter racks or chambers, sound attenuators, a mixing chamber, and dampers.