General Royal Air Handling Unit (AHU) is the primary equipment in an air system of a central hydronic system. It handles and conditions the air and distributes it to various conditioned spaces. General Royal air handling units (AHUs) have been designed and manufactured to meet the requirements of all kinds of space cooling and heating, such as office buildings, shopping malls, exhibition halls, airports, railway stations, hotels, factories and any other central air-conditioning systems.