Research on Indoor Thermal Comfort and Age of Air in Qilou Street Shop under Mechanical Ventilation Scheme: A Case Study of Nanning Traditional Block in Southern China

Xianfeng Huang,Chen Qu

doi:10.3390/su13074037

Abstract

In hot summers, air conditioning (AC) and mechanical ventilation (such as fans) are used as cooling modes that strongly influence the resultant indoor environment, like thermal comfort and air quality in the shops of a Nanning arcade street (qilou). The air circulation mode in shops greatly affects the indoor thermal environment and level of air freshness. The approaches for effectively improving the indoor thermal comfort and air quality are developed in qilou street shops with air-conditioner in a humid and hot region in southern China. Consequently, the purpose of this study is to assess different ventilation schemes in order to identify the best one. By using two indices, i.e., the predicted mean vote (PMV) and the age of air (AoA), in situ measurement and numerical simulation are conducted to investigate humans’ thermal comfort in extreme summer. Then, the indoor thermal comfort and AoA levels in summer under three different ventilation schemes (upper-inlet–upper-outlet, upper-inlet–bottom-outlet, and side-inlet–side-outlet) are comparatively analyzed through numerical computations of the indoor thermal environment. The results show that the upper-inlet–upper-outlet mode of the AC ventilation scheme led to the creation of a favorable air quality and comfortable thermal environment inside the shop, which will help designers understand the influence of the ventilation scheme on the indoor thermal comfort and health environment.

Highlights

Accepted: 2 April 2021With the acceleration of urbanization in southern China in recent years, due to the high building density of the traditional urban blocks in the humid and hot areas, the urban heat island (UHI) effect is aggravated, which leads to the deterioration of the micro-climate in the urban blocks
Indoor space differs from the outdoor space that makes up the qilou street environment; the customers staying in the shop experience variations in thermal sensation due to ventilation schemes that directly affect humans’ thermal comfort and air freshness
The urban island effect has raised attention to thermal comfort in urban blocks; this study investigated the indoor thermal environment of a traditional block, i.e., a qilou shopping street, in Nanning through field measurements and simulation computations based on the local climate conditions

Summary

Introduction

Accepted: 2 April 2021With the acceleration of urbanization in southern China in recent years, due to the high building density of the traditional urban blocks in the humid and hot areas, the urban heat island (UHI) effect is aggravated, which leads to the deterioration of the micro-climate in the urban blocks. High building density restricts the potential of natural ventilation in summer and increases the difficulty of thermal comfort and indoor air quality (IAQ) improvement in the blocks. Commercial buildings in these blocks provide consumption and recreational spaces that play a significant role in humans’ daily business activities. Their indoor thermal comfort directly affects their business and urban tourism [1]. A thermal discomfort or poor IAQ environment reduces the productivity of dwellers and even their wellbeing [4]

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