CHAPTER 1INTRODUCTIONThis chapter provides an introduction to the project. There are four sub sections to this chapter namely; background, statement of problem, objectives and project scope. The background chapter describes the global energy usage in building sector and the importance of energy efficient buildings for a developing country like Sri Lanka. Problem of statement describes the important if this project. Objectives describe the direction of the project and the expected outcome. Project scope highlights the extent of the study and project constraints.
1.1BackgroundBuilding sector consist of both commercial and residential buildings such as offices, schools, universities, hotels and shopping malls. Electricity and natural gas are the most common energy used in commercial buildings. In this report the energy consumption is discussed in terms of electricity. Electricity consumed in commercial buildings in Sri Lanka are mostly through air conditioning, lighting systems, elevators and pumps. Most buildings constructed in Sri Lanka are designed with minimum consideration towards the energy consumption and environmental impact. As a result of that the energy become a major role today. Therefore the energy efficiency, renewable energy and demand side management have become important areas for studies. In this report mainly focus on the development of some practical solutions to improve energy efficiency inside the commercial building while transforming near net zero energy building. Also identified that a significant amount of electricity is wasted due to inefficient design of HVAC and elevator systems.
Due to the energy crisis and environmental policies, most buildings asses their energy consumption and implement methods to reduce the energy consumption. This is achieved through conducting an energy audit.Energy audit is an official survey or study of the energy consumption and its objectives are to recommend steps for improving energy efficiencies, reducing the energy costs and wastage, improving quality. This is a procedure used to identify how energy is used for a given building, and to come up with ways to save energy or improve efficiency. Thus, primary objective of an energy audit is to assess the building energy consumption and provide energy saving opportunities through no cost or low cost improvements.
Energy auditing can be conducted according to various methods and standards. ASHRAE has defined three different types of energy audits such as ASHRAE level 1 which is a walk-through analysis (preliminary audit), ASHRAE level 2 which is an energy survey and detailed analysis; and ASHRAE level 3 which is a detailed analysis of capital intensive modification.
Level 1 auditing is conducted to understand the building configurations, to define the type and nature of energy system and to identify the potential for energy improvements. This type of audit provides to identify building performance compared to its associates, helps to develop a baseline for measuring improvements and helps make a decision if further evaluation is required.
Level 2 surveys takes into consideration the Building Envelope, Lighting, Heating, Ventilation and Air Conditioning (HVAC), Water Usage and other energy consuming equipment available in the building. Starting from a detailed analysis of the energy consumption to estimate base loads, seasonal variation and effective energy costs.
Level 3 auditing investigates deeper into the building operation and also considers the human factors influencing performance
In this report short term and long term implementations are given with a study on the process of developing, implementing energy management system and assessing energy efficiency in the faculty of engineering building while transforming the building into near net zero.
1.2Statement of the Problems
The temperature of the world has been increased within last two centuries since the industrial revolution. This has become a huge problem in the presence, as increased temperature results changes in the climate, various external cooling systems has to be used in the purpose of reducing the heat. With the last statement, another problem is raised; energy resources are declining rapidly, so these resources should be properly managed for the future.
Therefore the main aim of this project is to select SLIIT faculty of engineering building as a model and study on transforming this building to near net zero energy building.
1.3Objectives of the Research
Establishment of baseline for electrical energy use.
Identify the areas for energy consumptions and building integrated electricity generation.
Investigate the ongoing exist system to maximize the efficiency by reducing the waste of energy usage.
Identification of cost effective technologies and systems that are improving the energy efficiency of existing system.
1.4 Project Scope
This report covers the energy use of Lighting, Elevators, HVAC systems, Projectors and Computers in SLIIT faculty of engineering building. The main aim is to calculate the energy consumption of the SLIIT faculty of Engineering building in order to identify the potential energy savings. This project, includes the determination of establishment an baseline energy use, study and identify how energy is being used in SLIIT faculty of Engineering building and how much, where and how energy is used and identifies energy saving opportunities. A lighting simulation is performed to develop a better lighting system for the building with comparison to the existing system. And building simulation software is performed to develop an existing building with more renewable energy. Detailed energy audit was done by using power analyzer. But the energy audit may not be conducted with 100% accordance to the ASHRAE Level 2 auditing standards due to the limited budget and the equipment available does not fall under the required standards.
CHAPTER 2LITERATURE REVIEW2.1IntroductionReducing energy consumption of buildings has been proven to be more cost and resource-efficient than construction of new power plants. The research motivation for buildings integration is to identify technical and market drivers for energy efficiency on whole-building. In the National Renewable Energy Laboratory (NREL), Thermal Test Facility (TTF) researchers also give their attention on replacement of high-global warming potential (High GWP) refrigerants, improving health and durability of buildings, effectively using available solar resources.
This chapter intends to synthesize the current knowledge level regarding the research area and to establish an understanding to the project objectives. The energy consumption in buildings is reviewed in order to recognize how buildings consume energy. Sequentially, energy efficiency, establishment of baseline, is reviewed.
2.2Energy efficiencyThe energy conservation through energy efficiency in the building has obtained prime importance all over the world. There are four main aspects for energy efficiency in a building should include. First one is the nearly zero energy passive building design before actual construction. Then the second one is happening during the construction period by using low energy building materials. Thirdly use of energy efficient equipment for low operational energy requirement and final one is use of renewable energy technologies for various applications. There are four broad ways to reduce the energy consumption of building which ultimately results in mitigating emissions of CO2 emissions through energy conservation. These aspects are described as follows:
a. Comfort passive building design and its orientation for harnessing solar energy.
b. Energy efficient domestic appliance to conserve the building operational energy.
c. Building integrated renewable energy technologies.
2.3Energy consumption in buildingsDue to the oil crisis in the 1970s most developed countries focused on reducing the energy consumption as an attempt to conserve energy. Energy conservation was obtained through reduction of energy from demand side and by finding other sources of energy such as renewable energy.
In Sri Lanka, a large portion of electricity is consumed for cooling of spaces. This was justified through this project as the electricity used by air conditioning units accounted for 46.79% of total electricity supply. Energy consumption in buildings can be optimized through efficiency improvements to the equipment or building components such as building envelop. Many studies have highlighted the possibility of energy savings through minor improvements to the built environment. Therefore, almost all focus on reducing energy usage in the building sector through such improvements.
2.3.1Energy consumption in Sri Lanka
Key element to clearly understand the electricity consumption is to know the tariff structure of Sri Lanka. According to the present tariff structure in Sri Lanka, there are five major consumer categories (excluding street lighting). The five main categories according to the present tariff structure in Sri Lanka are:
Domestic – Supply of electricity used for domestic purpose in private residences.
Religious and Charitable – Places of public religious worship, homes for aged, orphanages and homes for the handicapped, which are specifically certified by the Director of Social Services as charitable institutions fall under this category.
General Purpose – Supply of electricity to be used in shops, offices, public buildings, educational establishments, and other premises not covered under any tariffs. There are the sub-categories under this section such as GP1, GP2, and GP3. GP1 supplies at each individual point of supply delivered and metered at 400/230 Volt nominal and where the contract demand is less than or equal to 42 kVA. GP2 supplies at each individual point of supply delivered and metered at 400/230 Volt nominal and where the contract demand is between 42 kVA and 1000 kVA. GP3 supplies at each individual point of supply delivered and metered at 11,000 Volt nominals and above.
Hotel – Hotels approved by the Sri Lanka Tourism Development Authority. This consists of three sub-categories namely H1, H2, and H3.
Industrial – Electricity used wholly or mainly for motive power or for electrochemical process in factories, workshops, foundries, oil mills, spinning and weaving mills, water supply and irrigation pumping stations, port and dock installations and other similar industrial installations. This consists of three sub-categories such as Industrial 1, Industrial 2, and Industrial 3.
2.4 Energy Audit
The purpose of an energy audit is to determine where, when, why and how energy is used in a facility, and to identify opportunities to improve efficiency’. Thus, an energy audit is a method used to identify energy consumption of a building in order to determine energy saving opportunities.
According to ASHRAE, energy auditing is categorized as level 1, level 2 and level 3 audits. These levels are categorized according to the depth of data gathering and analysis. This is used as a guideline across the world for energy auditing of buildings. Level 1 audit consists of a walk-through site assessment in which no-cost and low-cost energy saving opportunities and an accustomed view of capital improvements are identified.
Level 2 audit consists of the same activities as for the level 1 audit but with an additional engineering analysis to provide EEM recommendations which are in line with the financial plans and possible capital intensive saving opportunities. This includes a thorough analysis of energy costs, usage and building characteristics Level 3 audit is an extension of level 1 and 2 audits with a more detailed analysis which provides substantial recommendations and financial analysis for major capital investments. Further, level 3 auditing consists of monitoring. Type of auditing is selected based on the requirement, available resources and the budget.
2.5 Establishment of baselineBaselines create a benchmark for comparing energy performance from year to year. It allows to comparing energy performance before and after a change is made to the relevant building. Many studies have highlighted some basic steps in setting a baseline. These are,
Analysis of energy use and energy consumption.
The current energy sources are determined and energy consumption is evaluated.
Determine the areas with relevant energy use.
Determine the facilities/sites, equipment, systems, processes and staff that have a significant influence on energy consumption.
Identification of the potential for improvement of the energy-related performance.
The energy-related assessment must be updated at determined time intervals. However it must also be updated if significant changes have been made to facilities/sites, equipment, systems or processes.
As presented above after identify the baseline the buildings overall energy savings are calculated as follows:
29683315080Energy use in current year
00Energy use in current year
14426234592Adjustments to baseline energy use
00Adjustments to baseline energy use
left5107Total primary energy use in baseline year
00Total primary energy use in baseline year
right4592Energy savings in current year compared to baseline
00Energy savings in current year compared to baseline