Mean radiant temperature calculated based on radiant heat dissipation of human body addressing effect of emissivity of inner surfaces of envelope

Low-emissive coatings applied to the inner surfaces of the envelope effectively reduce the energy consumption of buildings, but significantly affect the radiant heat dissipation (RHD) of the human body. The mean radiant temperature (MRT) from the existing method cannot accurately estimate the RHD of the human body, which deteriorates thermal comfort thereby impeding the application of low-emissive coatings. This study proposes a calculation method of the MRT which accurately estimates the RHD of the human body. Case studies demonstrate that with the emissivity of the inner surfaces of the envelope decreasing from 0.9 to 0.1, the existing method inaccurately estimates the RHD of the human body with an error of up to 132%, while the proposed method reduces the error to less than 2.5%. The MRT from the existing method results in an error in thermal comfort evaluation (indicated by Predicted Mean Vote) up to 0.31 which fails the desired accuracy. The MRT from the proposed method effectively reduces the error in thermal comfort evaluation to be less than 0.01 satisfying the desired accuracy. Therefore, the proposed method contributes to the development of thermally comfortable and energy-efficient indoor environments with low-emissive coatings.