Investigation of physiological and subjective responses under composite air carrying energy radiant air-conditioning system

Abstract Air carrying energy radiant air-conditioning system (ACERS) as a new radiant air conditioning system has shown its important alternative technology to achieve current sustainable cooling/heating requirements. This study aims to further investigate the occupants’ physiological and subjective responses under the ceiling-sidewall composite ACERS. An experiment of the climate chamber installed with the composite ACERS was conducted under different thermal conditions. The results show that the composite ACERS can create a comfortable thermal environment , when the operative temperature varies between 23 °C and 30 °C. Physiological parameters , including blood oxygen saturation (SpO 2), pulse rate and skin temperature (local and overall) are measured to explore their relationship with operative temperature and thermal sensation. Statistical analysis demonstrates that SpO2 and pulse rate are not sensitive to the operative temperature, while the skin temperature is linearly related to the operative temperature. Also, these three physiological parameters both show significant difference in gender. Besides, it is found that the lowest temperature body part is the lower arm, but the hand is the most sensitive segment to the operative temperature, followed by the anterior calf and lower arm. Besides, the calculated comfortable temperature range for 80% acceptability is about 23.74 °C–30.40 °C from TSV and 23.57 °C–27.67 °C from PMV, demonstrating the environmental adaptability of people in their long-term life and the energy-saving potential of the composite ACERS as well. The findings of the study can help HVAC engineers to better apply the composite ACERS and further recognize the human physiological responses to the environment.