Analysis of the Thermal Environment in Pedestrian Space Using 3D Thermal Imaging

Xuexiu Zhao,Yanwen Luo,Jiang He

doi:10.3390/en13143674

Abstract

Pedestrian space is an important place for people’s outdoor activities. Its thermal environment affects pedestrian walking experience, route selection and physical health. This study presents a 3D thermography-based method to analyze and evaluate the spatial distribution of thermal comfort. The proposed 3D thermal image was generated using 3D city models captured by an unmanned aerial vehicle (UAV) and thermal images gathered by an infrared camera. It can visualize construction elements, but also simply output surface temperatures at selected points. This paper described the process of using 3D thermal images to analyze the built environment, and selected two pedestrian spaces as case study objects. Their thermal images and mean radiant temperatures (MRT) were obtained from field measurement data collected by a drone and infrared camera. The following findings were obtained: (a) the MRT difference in the pedestrian space between sunlit and shaded areas was more than 3 °C; (b) the MRT values at the measurement points near vegetation were lower; (c) when the ratio of street height to width (H/W) was larger, the MRT values at all measurement points varied slightly. These findings can be used for the designers to evaluate and improve the thermal environment in pedestrian space.

Highlights

Outdoor public space is an important living environment where people often fulfill leisure and entertainment activities
In order to fill this gap, this study presents a method to obtain three-dimensional (3D) thermal images by combining 3D models from aerial photography of unmanned aerial vehicles (UAV) with 2D thermal images simultaneously captured by an infrared camera
The thermal environment in pedestrian space is primarily controlled by the amount of the thermal environment in pedestrian space is primarily controlled by the amount of solar radiation, vegetation, paving materials etc., the methods for selecting appropriate evaluation solar indicators radiation,for vegetation, paving materials etc., of thethermal methods for selecting appropriate evaluation studying the spatial distribution comfort remain largely unclear

Summary

Introduction

Outdoor public space is an important living environment where people often fulfill leisure and entertainment activities. Well-designed and thermally comfortable space can attract more people to stay [1]. Eliasson’s research [2] in Gothenburg showed that the cleanliness index, temperature and wind speed have a great impact on the number of people in outdoor public space, accounting for more than 50%. In creating a comfortable thermal environment can control urban thermal stress, and effectively reduce the incidence of heat-related disease [3]. Kumar [4,5], it was found that if thermal comfort in the outdoor space is within the acceptable range, the occupant would spend more time outdoors. Thermal comfort is one of the important factors for the effective use of outdoor public space

Methods

Findings

Discussion

Conclusion