Predicted mean vote model for thermal comfort evaluation of pregnant women considering the effects of metabolic rate

In this study, on-site measurements of the summer air-conditioning environment in obstetric clinics of six hospitals in Guangzhou, China, and subjective questionnaire surveys of pregnant women regarding hot and humid environments were carried out. A total of 723 valid questionnaires were obtained. In order to determine the appropriate metabolic rate, three methods were used in this study to obtain three different metabolic rate values, including ASHRAE 55-2020 for healthy adults in a sedentary state 1.0 met, pregnant women after 5 months of pregnancy 1.2 met based on medical tests and the resting metabolic rate of pregnant women 0.66 met. Linear fitting was performed with three predicted mean votes (PMVs) and thermal sensation vote (TSV). The mean TSV (MTSV) and PMV models were established to estimate the actual thermal neutral value (25.3°C) and the predicted thermal neutral value (26.1°C) for pregnant women. The PMV model for pregnant women was linearly corrected, and the corrected PMV model coincided with the actual thermal sensory MTSV model. The corrected PMV estimate was 0.60 PMV + 0.17, and the corrected thermal neutral estimate was 25.3°C. Finally, a simplified model of the relationship between the PMV for pregnant women and the relative humidity, mean radiant temperature, wind speed and air temperature was obtained.