A Study on Energy-Saving Technologies Optimization towards Nearly Zero Energy Educational Buildings in Four Major Climatic Regions of China

Jing Zhao,Yahui Du

doi:10.3390/en12244734

Abstract

An educational building is a kind of public building with a high density of occupants and high energy consumption. Energy-saving technology utilization is an effective measure to achieve high-performance buildings. However, numerous studies are greatly limited to practical application due to their strong regional pertinence and technical simplicity. This paper aims to further optimize various commonly used technologies on the basis of the current national standards, and to individually establish four recommended technology selection systems corresponding to four major climatic regions for realizing nearly zero energy educational buildings (nZEEBs) in China. An educational building was selected as the case study. An evaluation index of energy-saving contribution rate (ECR) was proposed for measuring the energy efficiency of each technology. Thereafter, high energy efficiency technologies were selected and implemented together in the four basic cases representing different climatic regions. The results showed that the total energy-saving rate in severe cold regions increased by 70.74% compared with current national standards, and about 60% of the total energy-saving rate can be improved in cold regions. However, to realize nZEEBs in hot summer and cold winter regions as well as in hot summer and warm winter regions, photovoltaic (PV) technology needs to be further supplemented.

Highlights

Building energy consumption accounts for almost 40% of the primary energy in the United States or Europe, and nearly 30% in China [1,2,3]
This paper aims to optimize the design of various energy-saving technologies based on the current national standards under the consideration of appropriate indoor comfort range and mainly from the perspective of energy saving, and to establish four recommended technology selection systems corresponding to four major climatic regions, respectively, to achieve the goal of nearly zero energy educational buildings (nZEEBs)
The method to improve the performance of exterior walls is to optimize its U-value, which can be realized by the type of insulation material and the thickness of the insulation layer

Summary

Introduction

Building energy consumption accounts for almost 40% of the primary energy in the United States or Europe, and nearly 30% in China [1,2,3]. To reduce the consumption of building primary energy and achieve sustainable development, many countries, organizations, and associations have successively formulated plenty of energy-saving politics and goals. In the United States, new building energy codes released by the energy department in 2016 promote more than 30% energy savings compared to the codes from a decade ago [4,5]. Sweden set a target to achieve 20% and 50% of building energy savings by 2020 and 2050, respectively, compared with 1995 levels [7]. The Danish Building Regulations (BR) has set a goal of saving 25% of the energy use by 2010, 50% by 2015, and 75% by 2020 for all new buildings compared with 2006 standard levels [9]

Objectives

Methods

Results

Conclusion