Horizontal heat impacts of a bare facade on air temperature in an adjacent green plot within pedestrian heights in Beijing

Abstract

This study focuses on the horizontal heat impact of facades on the surrounding atmospheric environment at pedestrian heights. The results show that (1) the horizontal heat impact of a facade on the surrounding atmosphere was relatively uniform due to the homogeneous energy flux near the facade; (2) the significance of horizontal heat impacts gradually weakened with height, and the average significance was 48.74% in the spring and 47.81% in the summer; (3) energy factors, such as net radiation, soil heat flux, sensible heat flux, latent heat flux, and ground radiation, influenced the significance of the air temperature difference between the two observation sites where the investigation was conducted; one site was near the facade (distance = 0.30 m), the other one was far from the wall (distance = 10 m), and no dominant factor was found; and (4) the sensible heat flux was higher at the site near the facade than at the site far from the facade at the 0.05 significance level in the summer, which could be attributed to the strong horizontal heat impact from the facade. In contrast, the impact of the facade on the latent heat flux was not significant at the 0.05 significance level in the summer.