Experimental and Numerical Study on the Dynamic Thermal Response of Building Interior Decoration Coatings during Intermittent Air-Conditioning in High U-Values Buildings in China

Yanru Li,Lili Zhang,Xinyi Li,Yong Chen

doi:10.3390/en15051934

Abstract

Interior decorating coatings (IDCs) are the heat-transfer medium between indoor air and building walls, which mainly form the cooling load and are important in an indoor built environment. To explore the impacts of the precooling process of IDCs on indoor thermal environment of occupants during intermittent air conditioning, this paper investigated the dynamic thermal response of IDCs. Three representative coating materials were integrated to the external insulation wall and internal insulation wall, and their interior surface temperatures were experimentally tested under intermittent air conditioning operation in southern China. Moreover, a heat transfer model was established and verified to analyze the influences of IDC on the thermal response of the interior surface. During the pull-down process, the cold was accumulated in the IDC layer with small thermal diffusivity and could not be transferred into the wall inside, so that the largest temperature reduction was obtained, meaning that the indoor thermal environment could meet the setpoint in a short time. According to modelling calculations, the thick IDC with volumetric specific heat capacity less than 1 × 105 J/(m3·K) and small thermal conductivity integrated to the internal insulation wall was beneficial to increase the thermal response rate and had the better energy-saving efficiency.

Highlights

Publisher’s Note: MDPI stays neutralBuilding energy consumption accounted for 46.5% of Chinese total energy consumption in 2018, which was 2.147 billion tce [1]
The mainrates findings of interior this study are asoffollows: (1) Thermal response of the surface the internal insulation wall and external insulation wall met the law of negative correlation with the thermal diffusivity
(1) Thermal response rates of the interior surface of the internal insulation wall and exof the with small thermal diffusivity, the surface was ternal insulation wall met the law of negative correlation with thetemperature thermal diffusivity always lower,For making thewith indoor thermal environment more of the Interior decorating coatings (IDCs)

Summary

Introduction

Publisher’s Note: MDPI stays neutralBuilding energy consumption accounted for 46.5% of Chinese total energy consumption in 2018, which was 2.147 billion tce [1]. HVAC systems used to build the indoor environment would further increase the building energy consumption and carbon emissions. The building operation process accounted for 21.9% of the national carbon emissions [1]. Researchers have carried out many optimizations on building envelopes to reduce the energy consumption of HVAC systems [2,3], and found that intermittent operation of the air conditioner was an effective method [4–6]. The indoor thermal environment of an intermittently air-conditioned house suffers large fluctuations because of the on-off cycling of air-conditioning, resulting in the discomfort of personnel [9]. The intermittent air conditioning is not able to be considered as steady-state heat transfer, especially in the preheating/precooling stage [10]. The energy used to build the suitable indoor temperature involves a large part of the heat transferred through the building envelope. After turning with regard to jurisdictional claims in published maps and institutional affiliations

Methods

Results

Discussion

Conclusion