Thermal Comfort Index Comfort Air Conditioning Control

In a conventional HVAC control system, only air temperature and air humidity are controlled. As a result, the air-conditioned room is always not thermal comfortable enough, and the energy-conservation potentials is ignored either. The so-called comfort index-based control(CI control) is defined as the control of HVAC system, which takes thermal comfort index as the control parameter. After Cl control is adopted, the object of system will change from indoor air to occupants. Thus the thermal comfort level will be improved and the potential for energy conservation can be boosted.PMV and SET* are the optimal choices of CI control, as they successfully relate all the environmental variables with a person's thermal sense. Furthermore they have received comprehensive application in thermal environment engineering. Analysis of the application Cl control in the prevalent air-conditioning way shows that Cl control can give superior performance over conventional set-point control in terms of thermal comfort and energy utilization. In general Cl control can be categorized into direct and indirect method. In direct method the request for control algorithm and measurement instrument is relatively high, while indirect method is more flexible and applicable.Based on the study of the measurement and calculation methods of equivalent temperature, a model of compositive PMV and SET* sensor is put forwarded. Both the theory analysis and simulation verification to a simplified model have justified the model. At last the experimental development of the sensor is carried out, the result of system emulation shows that the model is reasonable. A commercial sensor can be developed from this model.