Investigation of Ventilation Behaviors in Mechanically Ventilated Residential Buildings in China

Yue Qi,Shen Wei,Xilei Dai,Lei Zhao,Junjie Liu,Dayi Lai,S.I Tanabe,J Kurnitski,H Zhang,G Cao,P Wargocki,M.C Gameiro Da Silva,C Inard,L Mazzarela,I Nastase

doi:10.1051/e3sconf/201911106048

Abstract

Mechanical ventilation system provides a more reliable, controllable, and comfortable way of ventilation than natural ventilation through an opened window. However, the operation of mechanical ventilation system cost energy. This study investigated the usage of natural and mechanical ventilation in 46 apartments in ten cities across five different climate zones in China by on-site monitoring and questionnaire survey. On average, the daily natural and mechanical ventilation durations were 11 hours and 7.2 hours, respectively. Large differences existed among climate regions and seasons. From north to south, as the climate became warmer, the usage of natural ventilation increased. From seasonal perspectives, natural ventilation duration was the longest in summer and the shortest in winter. The trend of mechanical ventilation usage was opposite to that of natural ventilation. Generally, as the outdoor air temperature increased, the duration of natural ventilation increased and the duration of mechanical ventilation decreased. This study proposed an outline to use thermal comfort, health, and energy saving as three motivations to analyze ventilation behaviors. Based on the obtained results, suggestions were made for achieving healthy, thermally comfortable, and energy efficient ventilation in residential buildings.

Highlights

By supplying outdoor air and removing indoor air in buildings, ventilation can create a thermally comfortable indoor environment with acceptable indoor air quality (IAQ) [1]
The average values of daily durations for NV and MV for all apartments were 660 minutes (11.0 hours) and 429 minutes (7.2 hours), which indicates that on a general level, mechanical ventilation is available in these monitored apartments, opening windows were the preferred way of ventilation for most of the households
This study investigated the ventilation behavior in Chinese dwellings equipped with mechanical ventilation systems

Summary

Introduction

By supplying outdoor air and removing indoor air in buildings, ventilation can create a thermally comfortable indoor environment with acceptable indoor air quality (IAQ) [1]. Ventilation can be achieved by natural forces such as wind and thermal pressures through window openings or by artificial means through mechanical ventilation systems [2]. A number of researchers, such as Rijal [3, 4], Andersen [5], and Pan [6] found that the proportion of opening windows was low under cold outdoor climate conditions, due to the thermal comfort considerations [611]. The reduced window opening duration may not provide sufficient ventilation to maintain an acceptable indoor air quality. Mechanical system provides a more reliable, controllable, and comfortable way of ventilation than opening windows. The mechanical fan can be operated continuously to ensure reliability, filter can be used to provide control over outdoor pollutants, and heat recovery unit can be used to reduce thermal discomfort

Methods

Results

Conclusion