Comparison of thermal comfort between radiant and convective systems using field test data from the Chinese Thermal Comfort Database

Abstract

This paper compares indoor thermal environment and thermal comfort between radiant and convective systems in continuous operating mode using large field test samples from the Chinese Thermal Comfort Database. Hypothesis tests are performed to compare thermal environment parameters and human subjective responses. We are concerned not only with statistical significance (P-value), but also with the effect size (d), since a small size effect would not have any practical significance. There is evidence of overheating of radiant systems due to high air temperature during heating season. There is no practical difference in air temperature between the two systems during cooling season. Indexes of radiant temperature asymmetry, vertical air temperature difference, air velocity and floor surface temperature are analyzed and compared. There is little practical difference in thermal comfort vote between the two systems at the same PMV interval. The neutral temperature difference is within 1.1 °C during heating season and is within 0.3 °C during cooling season between the two systems, which are narrower than the GB50376-2012 (2 °C during heating season and 0.5–1.5 °C during cooling season). This paper can provide reference for thermal environment design and thermal comfort evaluation under different HVAC systems.