Development Of Chamber For Thermostat's Performance Test

A thermostat is a switch that turns the heating or cooling equipment on and off when the sensed room temperature changes from the Set Point (temperature setting).A thermostat's most important is to provide comfort,it is commonly used in Central Air Conditioning system. Now many manufactures say their products have excellent performance and provide adequate thermal comfort, but in fact, many of these products can not carry out their promise. In order to evaluate a thermostat's performance and compare the performances between different thermostats, this paper summarizes a lot of important concepts, control algorithms and key issues such as System Lag, System Overshoot and Droop. A chamber was designed to fulfill the performance test based on the conclusions and the investigation of the functions and characters of many products. The chamber was used to simulate the environment of the room which is controlled by thermostat. The research and develop of the chamber mainly concludes mechanical structure design, HVAC design, hardware and software design of control system. The control system in chamber concludes functions such as data collect, HVAC and display equipment control and communication between chamber and control computer. Communication interface with user, the heat algorithm of the system, data saving and management are the main functions of the control computer. Some products were tested by the equipment and test reports were finished by the program of the equipment after debugging it.The conclusion and the chamber of this paper may be useful for the engineer of thermostat designing and validate their products and helpful for HVAC engineer to choose proper thermostats.