Improving Energy Consumption of Existing Buildings in Shanghai - Research Paper Example

Table of Contents

Improving EnergyConsumption of Existing Buildings in Shanghai by Retrofitting Methods3

Introduction3

Proposal4

Project Management Plan4

1.0 Literature Review5

1.1 Growth and Consumption in China6

1.2 China’s Existing Building Opportunities7

1.3 Shanghai Climate Analysis8

1.4 Active and Passive Retrofitting Technologies9

1.5 Passive Design and Application for Retrofitting10

2.0 Building Energy Simulation and Software12

2.1 Energy Simulation Techniques12

2.2. Energy Simulation Software13

DoE-213

EnergyPlus14

TRNSYS14

DesT14

2.3 Selection of Software15

2.4 Simulation Methodology15

• Improving EnergyConsumption of Existing Buildings in Shanghai by Retrofitting Methods
  • Introduction

This projected aimed to come up with various ways and suggestions to optimize energy consumption that is aligned towards cost minimization. To achieve this, the project selected a medium size building in Shanghai China. Various energy performance evaluation tools were applied to measure energy efficiency. In addition, the project was organized in three stages. The stages included:

• A study of Shanghai climate and locally used architectural designs that would affect the prevailing energy performance improvement methods.
• A ten-day field study that included workshops in China in the month of July 2017
• Summarizing the findings, results, solutions, and proposal in form of a report applying the Deignbuilder Analysis Technique.

In this project, the project team was commissioned by the Victoria University to act and research on behalf of Lab Architecture Shanghai. The team was tasked to do an assessment on the probable retrofitting methods that can lower energy consumption in the selected building. The project team was to make sure all the deliverables and standards outlined in the project plan by the project managers were followed and achieved for the results to be accepted by the Lab Architecture Studio in Shanghai.

• • • Proposal

The project followed various guidelines in accordance with the proposals that were laid down in the proposal and literature review. The areas covered are;

• The growth and energy consumption rates in China
• The existing building opportunities in China
• An analysis of climate
• Active and passive retrofitting technologies
• The building energy simulations and software
• Techniques used in energy simulation
• Techniques used in energy simulation
• Software selection procedures
• Simulation methodology
• The feasibility of the suggested solutions
• The economic impacts of retrofitting technology is applied

Besides, the project carried out a comprehensive research on all probable solutions that can have an impact on the building selected. This enabled the team to be able to gather very crucial information on the subject to include in this report. Notwithstanding, the initial stage of the project laid a good foundation for stage two that involved a travel to China.

• • • Project Management Plan

As outlined in the Project Management Plan in the coursework for last semester, various key points were considered. These involved: Project objectives, deliverables, project out-of-scope, main assumptions and milestones, organization breakdown structure, rules for the team, breakdown of work, risk management plan, budget, communication plans, quality assurance as well as the pre-training. In general, the aim of the Project Management Plan was to outline all procedures for assessment, auditing, inspection, design, computational modeling, project management as well as the project delivery.

• • 1.0 Literature Review

Shanghai is one of the highly populated cities in China. As a result of this, it consumes a lot of energy that in total makes China be identified as the world’s highest energy consumer with an inclusion of the overreliance on fossil fuels. An approximate of 85 percent of all building in China falls under the high energy use category. Notably, the government of China has tried to come up with various ways aimed at reducing energy consumptions. Some of these policies include retrofitting the assets and encouraging the construction industries to build structures that are energy efficient.

There are numerous chances for developing energy efficient retrofitting. In addition, there exist many energy-saving options that can be applied in retrofitting building in China. However, questions may arise on how effective the options may be as well as in which climatic conditions.

This project examined a number of retrofitting alternatives by applying computerized building simulation software. The software was utilized to compare and analyze a number of retrofitting technologies that were available to come up with the most feasible cost-effective option. Various variables influence the effectiveness of retrofitting methods, which include climate, heat, location, the behavior of the occupant, air conditioning (HVAC) and ventilation, electric systems of the building, construction methodology among others. The potentiality of reduction of energy may either be caused by one or a combination of these variables.

Coming up with a clear guideline on the best retrofitting methods in various buildings and specific climate will be a great deal for Shanghai’s population. This will be applicable when they decide the type of construction practice or technology that will bring about desirable results. For instance, current studies state that retrofitting lighting system is the most energy saving method in China as compared to bulky insulation upgrades.

In this project, the computerized simulation method was helpful during the process of coming up with the most effective retrofitting technologies suitable for the building. It also tested the feasibility as well as the potential hindrances in its adoption notwithstanding the identification of suitable technologies in retrofitting for advanced connections.

• • 1.1 Growth and Consumption in China

In the recent times, most China’s energy policies have been directed to building and construction sector. This is because about 20 percent of the total energy consumption in China is attributed to this sector with the main reason being urbanization. According to the Oak Ridge National Laboratory and the United States (2016), about 21 million people move from rural to urban areas.

Reduction of energy operational costs is a gradual process that can be achieved by construction of sustainable buildings with efficient design plans. Over the years, Engineers have tried to come up with various business model options aiming to lower building energy consumption in the commercial and industrial sector. Equally, the dynamism of technology has enabled them to come up with innovations based on retentions of old buildings and improving designs for new developments (Calderone, 2015).

Building energy use reduction in Shanghai China is an end result of environmental conservation and sustainability. A continued building energy performance will, in the end, have an impact on the global energy usage since China has a large population ending up with high energy consumption (Li et al., 2010). The project came up with Shanghai China city because it represents a modern society with various structures aiming to meet market demands. In addition, China is faced with a danger of high energy demand and the use of unclean energy which requires new innovations towards energy conservation and sustainability (Li et al., 2010).

This study identified that in controlling carbon emissions first, the goal of sustainability is achievable. According to Liu (2016), the government’s emission reduction target by 2020 is set at 45 percent. The global emission goal will only be achieved by coming up and adopting clean energy alternatives such as retrofitting.

• • 1.2 China’s Existing Building Opportunities

Hartman (2000) had projected that 25 percent of total primary energy use in China by 2010 will be from the building sector. In addition, by 2017 the consumption would rise to above 70 percent of the existing buildings. Notably, about 85 percent of the current buildings were projected to be in the category of high energy consumption (NREL, 2001). China boasts of an economic boom resulting majorly from the building industry since 1980s economic reforms with about 60 billion square meters new buildings (Ya-Xin& Zhang Xu, 2006).

Retrofitting existing buildings comes with some advantages as opposed to demolitions. In cuts down wastage that would otherwise arise from demolition such as excavation and energy to be used during a new construction. In general, there were three key factors identified to influence energy consumption in the Chinese commercial building sector. These included:

• Heating and cooling. The northern and temperate part of the country was identified to account in heating for about 40 percent of the gross urban energy consumption (Traugott. 1999)
• Large public buildings. Fan (2008) attributed about 4 percent of the total building for large public buildings consuming 22 percent of total structure’s energy. Large buildings contain a large glass area that has no shading f insulation resulting in excessive energy loss hence summer cooling and winter heating.
• Low-performance building envelops. The project noted less regard to energy efficiency in the existing buildings. For example, thermal properties of building envelopes in China are built with less regard to airtightness as compared to over similar climate developed countries.
  • 1.3 Shanghai Climate Analysis

Shanghai experiences a four-season sub-tropical climate. During winter, the climate is mostly chilly and there exist westerly winds. This condition greatly lowers the temperatures during the night to even below freezing point (Cheng &Yuexin, 2012). On the other hand, summer climate is hot and humid and in some case temperatures rise above 35 degrees. The most favorable seasons are spring and autumn. However, at times the two seasons still experience heavy rains with an average temperature range of 4.2 to 27.9 degrees (Kan& Stephanie, 2007). Zhang and Song (2008) identified that the monthly sunshine percentage of Shanghai was between 34 percent in March to 54 percent in August and an addition of 1,895 hours of sunshine per year. Notably, summer noontime temperatures range from 35 to 36 degrees where humidity is extremely high.

Generally, Shanghai experiences hot and humid summers and exceedingly cold winters. In most cases, Shanghai city experience a temperature summer rage of 27 to 30 degrees. However, for the months of September, October, and November temperatures gets low though still mild. Winter is usually during the months of December, January, and February. During winter, temperatures appear pleasing and mild despite spring season rains.

• • 1.4 Active and Passive Retrofitting Technologies

Construction of buildings should take into consideration various factors during the planning stages. This should involve building material’s thermal characteristics and reduction of internal loads. Similarly, maximization of natural ventilation and daylighting should be considered to ensure a reduced energy requirement through HVAC systems (Guoping, et al., 2010). These considerations can involve the use of thermal efficient glazing, improved insulation resistance, lowering of air leakages as well as the introduction of effective shading devices. These measures expressively put a cut in the overall cooling and heating needs consequently lowering the HVAC systems and components loads hence less operating energy.

Basic thermodynamic principles can be utilized effectively to lower overreliance on mechanical heating and cooling. For instance, use of natural ventilation, thermal-mass storage, radiant cooling as well as passive solar control. JinlongOuyang (2009) asserted that it is important to comprehend the technical characteristics and performance of architectural components, systems, practices in construction and maintenance. These factors enabled the achievement of auniversal building performance in line with energy reductions.

Chen et al. (2013) outlined a number of new technologies that were developed in various projects. This included underfloor air distribution systems, ice storage systems, radiant cooling and heating, integrated photovoltaic, fuel cells, and co-generation and tri-generations. They also outlined systems such as sulphur and magnetic-induction-based lighting systems, LED lighting, high-performance glazing as well as other more developed digital controls and sensors.

There existed a direct relationship in the evolvement of technology to systems and behavior. HVAC systems’ environmental performance was improved by use of recent technologies. For example, underfloor air-conditioning is highly adaptive and flexible when it uses the stratification process in conditioning the air spaces containing less volume compared to the traditional overhead structures. As a result, the fun power that accumulates about 40 percent of gross HVAC energy is reduced. The resulting system was highly flexible and can provide an improved thermal comfort and indoor air quality and an end result of cost reductions.

• • 1.5 Passive Design and Application for Retrofitting

Systems that utilize the readily available sources of energy in the environment are known as passive systems. The systems don’t use energy from gas and electricity. Through these systems heating and cooling, loads are optimized to efficiently make use of natural air flows and solar radiant energy. This project aimed to investigate the retrofitting system of a building in Shanghai so as to improve its heating and cooling loads. Feist (2006), carried out a study in Germany and identified that passively designed structures, for example, Darmstadt Kranichstein is a great design towards discovering the solutions of future building load reduction.

As earlier identified, the climate in Shanghai was to be an important factor in this project. This was because retrofit plans must take into consideration the amount of energy that will be involved in the transfers. Therefore, the different climatic zones in China will dictate the appropriateness of the selected passive design. Wilkinson (2015) identified that Shanghai experiences hot summer and cold winter zones with mild climate as a result of coastline proximity.

Further, Wilkinson (2015) states that with Shanghai experiencing seasonal temperatures going above 35 degrees Celsius in summer and below zero in winter, the city is in an inconsistent climatic zone. During the 1st International Conference on Sustainable Buildings and Structures, glazing research revealed that Shanghai had the least impact in the reduction of heating and cooling. This is despite the replacement of argon with aerogel in double glazed windows.

Essentials of passive systems in this project were categorized into three heat transfer methods, which are conduction, convection, and radiation. This breakdown was to allow a refined analysis of Shanghai’s passive design potential.

Environmental evaluation of the buildings was got from the Chinese Bureau of Environmental Protection (Doing Business 2015). Where there was a large surface area reached by the sun, passive energy was taken to be feasible. The following systems that use radiation were studied:

• Application of reflective surfaces to minimize energy retentions.
• Heat on surfaces involving ambient outdoor temperatures and reflected radiation.
• Overhangs that would absorb winter sun and protect from summer sun
• Windows to wall ration optimization
• Orientation arising from surfaces choice for probable glazers

Roofing materials whether able to absorb or reflect plays a key role in choosing a passive design to fit in a specific environment. Heat gain through the roof increases the cooling load and accounts for about 70 percent of gross heat gain. Shanghai being just 3 degrees north of the tropic zone makes it prone to tropical zone climate and all changes in climate require that roofing considerations be made. In general, appeasing heat gains through roof structures and combining glazing and infiltration control methods was identified to bring about a great solar gain control remedy.

• • 2.0 Building Energy Simulation and Software
  • 2.1 Energy Simulation Techniques

It is crucial to analyze building energy when coming up with the most appropriate energy retrofit choice. The importance of this simulation was to clearly demonstrate the building energy consumption levels and come up with suggestions on the possible energy-saving measurement ways. This project applied two methods to building energy consumption. These are:

• Calculations grounded on static heat transfer theory and climate data, for example, the degree-day, expanded degree-day, and equivalent operating hour approaches.
• The computer simulation method and other interlinked software calculation modules, for example, the heat equilibrium, weighted coefficient, and heat net approaches (Pan Yi Qun, 2004-09).

Notably, these methods needed elaborate simulation software and computers. The computerized software was developed that was to guarantee high accuracy level by use of quality input data gathered. Energy efficiency opportunities that were gathered through the Shanghai field trip were specifically used in the computerized simulations processes.

Remarkably, the current prevailing energy simulation software contains two methods, which are a sequential and simultaneous simulation. Sequential follows lspE order, which follows the order of first-load calculation, HVAC and facility calculation, and last economic calculations. On the other hand, simultaneous simulation carries out load, system, and system calculation at the same time and combines them later.

• • 2.2. Energy Simulation Software

The dynamism of climate, sun positions, and intensity as well as the thermal storage capacity of the material makes it crucial to apply dynamic calculations for better results. Consequently, the ongoing developments in computer software and hardware combined with the queries targeting building energy consumption, a number of simulation software in building energy have been developed. The most common software in the current world includes doE-2(eQuest), Energyplus, and Dest (Qiang, et al., 2015).

• • • DoE-2

This was developed by Lawrence Berkeley National Laboratory and was initially published from 1979 to 1999. It has become one of the most used simulation software in the world. It was later developed to become eQuest (Ching, et al., 2007). This software utilizes a transfer function method with sequential simulation and contains four modules; lspEloads, system, plants, and economics that operates. Ching, et al. (2007) identified that this software is largely accurate and can simulate complicated structures despite it using exclusive fixed program language and mode that are time-consuming to generate.

• • • EnergyPlus

This was first released in 2001 and has since become the most accepted simulation software in the world (Chin, et al., 2007). The developers were Lawrence Berkeley National Laboratory, the University of Illinois, the U.S Army Construction Engineering Research Laboratory, and other organizations. In contrast with the doE, this software uses simultaneous module simulation of loads, systems, and facilities. The three are developed to adjust with each other to compute dynamic heat transfer as well as the heat transfer to calculate the load. Additionally, users can set their desired length and simulate loads in one hour at minimum gain. This is because the software can optimize the sky, sunlight, and lighting simulations in the model (Qiang, et al., 2015). The same software can be applied in a multi-are airflow analysis, solar energy application program design, and building thermal property research (Qiang, et al., 2015).

• • • TRNSYS

TRNSYS(Transient Systems Simulation) was first published in 1975 and developed by the Solar Energy Lab at the Mechanical Engineering College at the University of Wisconsin (Quan&Yuang Chi-Chung, 2007). In this software, users are able to set the module that suits their purpose by combining several modules. Qiang, et al. (2015) identified that the modules are attached to each other. Therefore, users are able to develop basic geometric models and carry out step by step computations after designing complex customized user modules for simulation.

• • • DesT

DesT (Designer’s simulation toolkits) was first developed by the Building Science Department of Tsinghua University with an original name as BTP (building thermal performance). The distinguishing feature of this software is it’s where it applies divided-phase simulation through its numerous independent modules (Quan&Yuang Chi-Chung, 2007). It has its basis on various modules that calibrate the simulation based on the systems, hydraulics, and designs phases of the building.

• • 2.3 Selection of Software

Despite Energyplus being complicated and time-consuming to use and having a user interface not being much intuitive as the rest, it was the most flexible to use. This was because of its ability to simulate complex building geometry and HVAC systems. Having prior experience with the DesignBuilder software as introduced in the Victoria University coursework posed an advantage to use Energyplus compared to other unfamiliar software. This also enabled reduction of user-related errors that would have been brought about by lack of knowledge. Therefore, this maximized the effectiveness during the simulation process.

This project hence used Energyplus(via the Design builder interface) during the simulation of Shanghai retrofitting options. Pan Yi Qun (2004-09) asserted that Energyplus is a powerful tool to apply in developing building systems and in the selection of various building facilities compared to other software.

• • 2.4 Simulation Methodology

Computation building energy simulation program of the Energyplus was used to develop a simulation model of the case study site. The procedures followed were as follows:

• Established a base reference building model. The featured data included building function, population, geometry, occupancy times, HVAC system type, configuration, operation and set-points, connected equipment and usage, lighting systems, and construction element properties.
• The project obtained actual energy consumption data for the reference building. This data was used as base data to verify the outcomes of the reference model.
• Obtained the Shanghai ambient weather data for an appropriate test reference year (TRY)
• Refined the simulation model base according to real data obtained during the site visit and energy consumption data for the building type as obtained during the study tour.
• The project identified some easy quantifiable retrofitting technologies for simulation in comparative energy models. They included: improvement of the thermal performance of construction elements (roof, walls, floors, and windows), maximization of the use of passive heating or cooling sources, improvement the efficiency of HVAC distribution systems (pumps, fans, and introduce forms of heat recovery), improvement of lighting systems (for example, the use of energy-efficient lamps or increasing solar access), revision of control and behavior of users (for example, changing of indoor temperature settings).
• Conducted a step by step simulation to compare the reference building against a test scenario including energy-saving technologies.
• Calculation of the simple payback period of the utilized retrofitting technology and analyzed the economic benefits of each option with respect to the base reference model.

The project proposals were to identify retrofitting g solutions that would have enabled an improvement in energy efficiency in buildings, systems, and equipment. The suggestions were also to propose guidelines to reduce internal heating and cooling loads, maximization of natural light and ventilation and lower the overreliance on HVAC system. Overreliance on HVAC can be attained by improving window glazing, minimizing air leaks, putting insulations, and installation of effective shading. The project was to find out if mechanical systems would be the weakest link while developing a reliable energy performance and efficiency.