Measurement and evaluation of indoor thermal environment in a naturally ventilated industrial building with high temperature heat sources

• The characteristics of measured thermal environment were clearly different from civil building.
• The measured WBGT coincided with the worker's perception toward the thermal environment.
• The proposed indoor WBGT prediction model can predict WBGT more accurately.

In this study, indoor thermal environment and workers' perceptions were investigated at four different locations in a naturally ventilated industrial building with high temperature heat sources in summer and winter. The results demonstrated that the differences between the mean radiant temperature and air temperature were between 0.8 °C and 5.3 °C in summer and between 1.6 °C and 11.0 °C in winter, and the average air velocity generally ranged from 0.3 m/s to 1.5 m/s. Moreover, the average wet bulb globe temperature (WBGT) was between 27.3 °C and 29.0 °C in summer and between 5.7 °C and 8.9 °C in winter, which coincided with the workers' perceptions of the thermal environment. The WBGT thus may be one of the potential indices to evaluate the indoor thermal environment in summer and winter. A prediction model for the indoor WBGT using the thermal environmental parameters was developed strictly based on the law of analogy for heat and mass transfer. The predictions agreed quite well with the measured data for WBGT of between 24 °C and 30 °C in summer and 2 °C–10 °C in winter, and the absolute differences between the predicted and measured WBGT were between 0 °C and 1.1 °C with an average of 0.3 °C in summer and between 0 °C and 1.2 °C with an average of 0.5 °C in winter. Therefore, the proposed indoor WBGT prediction model was valid and can be used to determine the acceptable thermal environmental parameters during the design stage for naturally ventilated industrial buildings with high temperature heat sources.