Commercial systems differ from domestic systems generally in size (greater than10kW), but also due to different building code requirements. These systems usually feature ducted air distribution, fresh air provision, filtration systems, acoustic treatments and more sophisticated temperature and/or humidity control equipment. Heating is economically achieved through reverse cycle operation or by electric heaters.

Package Systems

These systems are located outside, usually on a rooftop platform but also at ground level. They contain one or more compressors, evaporator fan & coil set & condenser fan & coil set. Used in situations where the outdoor package unit can be located close to the air-conditioned space, the cool air is delivered by insulated ductwork. A high percentage of air is returned by a separate duct system from the air-conditioned space to the unit via a bank of filters. A small percentage of fresh air is also introduced at the point of air return.

Zone control can be achieved most economically by installing a number of independent package units, thereby also reducing the point load of equipment on roof structures. Alternatively, electric duct heaters or variable air volume devices may be used.

Split Systems

These systems are used to isolate the noise and vibration of the compressor from the air-conditioned space. The indoor unit, consisting of a fan, filters & cooling/heating coil is generally mounted in the ceiling space or in a plant room. Conditioned air is delivered via insulated ductwork from the indoor unit and a high percentage of air is returned by a separate duct system from the air-conditioned space via a bank of filters. A smaller percentage of fresh air is also introduced at the point of air return.

The outdoor unit, consisting of compressor, condensing coil & fans, is located some distance away, either on a roof top platform or at ground level. The two units are linked by insulated refrigerant pipework at distances of up to 50m.