A comprehensive evaluation index for indoor thermal comfort and energy utilization

The dual demands for energy saving and high-quality indoor environment present new challenge for building heating. A new evaluation index CEUC (Comprehensive Energy Utilization Coefficient) that can simultaneously evaluate the energy efficiency and thermal comfort performance is proposed in this article. CEUC is calculated using thermal comfort index PMV (Predicted Mean Vote) and PPD (Predicted Percent Dissatisfied). It takes only the heat entering human activity zone as effective utilized heat, and radiation heat is considered. Two typical heating terminals -air conditioner and floor radiant heating are selected to verify CEUC. Data show that the air supply speed of convective heating has greater impact on CEUC than that of the temperature. In practice, lower air supply temperature should be set as much as possible, and air supply angle should be less than30°. Taking CEUC as the optimization goal, the optimal wind speed for air conditioner in the room model established in this article is 4–5 m/s, and the optimal temperature for floor radiation heating is around 38 °C. The accuracy of CEUC is verified from the perspectives of energy utilization efficiency and thermal comfort.