Sustainable Buildings’ Energy-Efficient Retrofitting: A Study of Large Office Buildings in Beijing

Shiyu Wan,Grace Ding,Yisheng Liu,Goran Runeson

doi:10.3390/su14021021

Shiyu Wan, Grace Ding + Show 2 more

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https://doi.org/10.3390/su14021021

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Abstract

Energy-efficient retrofitting has emerged as a primary strategy for reducing the energy consumption of buildings. Buildings in China account for about 40% of total national energy consumption. Large office buildings account for the most. Less than 5% of the building area of existing office buildings is energy efficient. Energy-efficient retrofitting for sustainable buildings is a complicated system that involves various sustainable dimensions and operational technical schemes. Making multi-criteria decisions becomes a challenging problem for stakeholders. Based on the theory of sustainability, this paper establishes a sustainable analysis framework to guide stakeholders to select an optimal technical combination of energy-efficient retrofit measures for large office buildings. Based on empirical data collected in Beijing, a number of energy efficiency measures are selected, tailored and applied to a virtual model of a typical large office building. Technical features and the energy performance are simulated accordingly. The energy consumption, energy-saving ratio and lifecycle costs are derived to identify the optimal configuration. The outcome of this research offers a feasible technical plan for stakeholders relating to technical design and design making. The study finds that an LED lighting system and frequency conversion device for the cooling water chiller cannot only sufficiently reduce the building’s energy consumption but also perform economically. Different thermal insulation materials for reconstructing the building envelope have no obvious effect on the thermal performance in comprehensive simulations of technology combinations. The sustainable analysis framework offers theoretical and practical support and can be used as a reference for the other types of buildings in future research.

Highlights

Climate change is a challenge all over the world
As public buildings, based on the total floor area and energy intensity except for heating, office buildings can be divided into two types: (1) large office buildings that make use of a central air-conditioning system, where a single building covers over 200,000 square meters, and (2) ordinary office buildings
Where ε stands for the energy-saving rate, E represents the energy consumption after the energy-efficient retrofit and E0 represents the original energy consumption before the energy-efficient retrofit

Summary

Introduction

Climate change is a challenge all over the world. Responding to climate change, China has pledged to considerably reduce its CO2 emissions to reach carbon peak before2030 and achieve carbon neutrality before 2060 [1]. Responding to climate change, China has pledged to considerably reduce its CO2 emissions to reach carbon peak before. Energy consumption in buildings accounts for nearly 40% of the total primary energy consumption in China [3]. Public buildings (in China, these are not limited to government-owned properties and include office buildings; hotels; commercial buildings; science, education, culture and health buildings; communication buildings and transportation buildings [4]) account for approximately one-fifth of the total energy consumption of buildings [4,5]. Existing office buildings occupy about 4.5 billion square meters of total floor area, and less than 5% of floor area achieves the required energy efficiency [6]. Energy consumption in existing office buildings is markedly high in terms of heating, cooling, ventilation and lighting.

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