Investigation of the relationships among temperature, illuminance and sound level, typical physiological parameters and human perceptions

Abstract

Human perceptions are stimulated simultaneously by multiple environmental factors, such as temperature, illuminance, and sound level. Meanwhile, the human body regulates physiological parameters to maintain balance with changes in the indoor environment. This means that human perceptions can be expressed as a function of typical physiological parameters that vary with the ambient environmental conditions. Therefore, a series of human subject experiments were conducted under 144 controlled indoor environment conditions. Human perception and five physiological parameters, i.e., systolic blood pressure, diastolic blood pressure, heart rate, and skin temperatures at the wrist and forehead, under stimulation by different combinations of temperature, illuminance, and sound level, were measured to determine whether any physiological parameters are affected by environmental factors, and if so, then which parameters. The experiments were also conducted to identify which physiological parameter generated the greatest amount physiological information that could be used to represent the human perception. The study revealed that physiological parameters were affected to varying degrees by multiple environmental factors and had different degrees of correlation with human comfort votes. Moreover, the measured skin temperature at the wrist (STwrist) varied linearly with the air temperature (t) and exhibited an S-shaped relationship with thermal comfort vote (TC). In addition, the quantitative relationships between t and STwrist and between TC and STwrist were established. By combining these two quantitative relationships, the temperature ranges and acceptance rates under different thermal comfort vote ranges were obtained, which coincide with the results of previous research and satisfy the requirements of ASHRAE Standard 55–2010.