Survey on the Indoor Thermal Environment and Passive Design of Rural Residential Houses in the HSCW Zone of China

Rui Rui,Du Du,Shi Shi,Pan Pan,Zhang Zhang,Chen Chen

doi:10.3390/su11226471

Abstract

Despite their high energy consumption, rural residential houses in the hot summer and cold winter (HSCW) zone still have a generally poor indoor thermal environment. The objective of this study was to understand the current status of the indoor thermal environment for rural residential houses in the HSCW zone and analyze its cause in order to develop some strategies for improvement through passive design of the building envelope. Face-to-face questionnaires and interviews, air-tightness testing, and temperature and humidity monitoring were conducted to understand the building envelope, energy consumption, and indoor thermal environment. Then, some passive design strategies were simulated, including the application of functional interior materials such as hygroscopic and phase change materials. An overall passive design for the building envelope can increase the room temperature by 3.6 °C, reduce the indoor relative humidity by 12% in the winter, and reduce the room temperature by 4.4 °C in the summer. In addition, the annual energy-saving rate can reach ~35%.

Highlights

In China, the hot summer and cold winter (HSCW) zone mainly includes the middle and lower reaches of the Yangtze River and its surrounding areas
In rural China, the improving economic level and increases in the number and frequency of electrical appliances caused rural residential commercial energy consumption to reach 243 million tons of coal equivalent (TCE) in 2017; this accounted for 25.31% of the total commercial energy consumption of buildings in China [3]
The average indoor temperature of rural residential houses in the HSCW zone can reach 29.7 ◦C in the summer, which indicates that the indoor thermal environment falls beyond the 80% acceptability range of the adaptive model defined by ASHRAE standard 55 [5]

Summary

Introduction

In China, the hot summer and cold winter (HSCW) zone mainly includes the middle and lower reaches of the Yangtze River and its surrounding areas. In this zone, the average temperature in the hottest month is 25–30 ◦C; it is the hottest area in the world at this latitude except for arid deserts. This zone is very humid; the relative humidity in most cities is 75%–80% and sometimes even 95%–100% [2] These climatic features make the indoor thermal environment improvement and passive design of rural residential houses in the HSCW zone more difficult. Despite the high energy consumption, rural residential houses in the HSCW zone still have a generally poor indoor thermal environment. In Shanghai, Changsha, and Chongqing, houses were observed to have a high relative humidity of 60%–100% [7]

Objectives

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Conclusion