The unit consists of ducting fitted with various air conditioning components. Airflow is generated by an axial flow fan and in the airflow, heaters, cooling coil and steam humidifier connection is provided. Cooling circuit consists of a hermetic compressor; air cooled condenser, thermostatic expansion valve and evaporator (i.e. cooling coil). Measurements of various parameters Torn cooling cycle and heating cycle are provided and students can easily visualize and understand the basic principles of air conditioning.