A Central Air Handling Unit (CAHU) is a critical component of any HVAC system. It is responsible for the distribution of conditioned air throughout a building. It is typically located in the attic or basement and is composed of a fan, filter, and coil. The fan is responsible for pulling air into the unit and pushing it out into the building. The filter removes any airborne particles that could potentially damage the system. The coil is responsible for cooling or heating the air before it is distributed throughout the building. The CAHU is a key component in the overall efficiency of an HVAC system as it helps to maintain the desired temperature in the building. It is important to regularly maintain and service the CAHU to ensure it is operating efficiently and effectively.