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Electrical Systems

G|PRO Green Professional Building Skills Training



Copyright © 2012 by Urban Green Council, U.S. Green Building Council New York. All rights reserved.

None of the parties involved in the funding or creation of the Course Manual, including Urban Green Council, its members, or its contractors, assume any liability or responsibility to the user or to any third parties for the accuracy, completeness, or use of or reliance on any information contained in the Course Manual, or for any injuries, losses, or damages (including, without limitation, equitable relief arising from such use or reliance). Although the information contained in the Course Manual is believed to be reliable and accurate, all materials set forth within are provided without warranties of any kind, either express or implied, including but not limited to warranties of the accuracy or completeness of information contained in the training or the suitability of the information for any particular purpose.

Urban Green Council devoted a significant amount of time and resources to create this GPRO® Course Manual for Electrical Systems, 2012 edition, V.1.5. Urban Green authorizes individual use of the Course Manual. In exchange for this authorization, the user agrees: đƫ to retain all copyright and other proprietary notices contained in the Course Manual đƫ not to sell or modify the Course Manual đƫ not to reproduce, display, or distribute the Course Manual in any way for any public or commercial purpose, including display on a website or in a networked environment. Unauthorized use of the Course Manual violates copyright, trademark, and other laws and is prohibited. The text of the federal and state codes, regulations, voluntary standards, etc., reproduced in the Course Manual is used under license to Urban Green Council or, in some instances, in the public domain. All other text, graphics, layout, and other elements of content in the Course Manual are owned by Urban Green Council and are protected by copyright under both United States and foreign laws.

As a condition of use, the user covenants not to sue and agrees to waive and release Urban Green Council, its members, and its contractors from any and all claims, demands, and causes of action for any injuries, losses, or damages (including without limitation, equitable relief) that the user may now or hereafter have a right to assert against such parties as a result of the use of, or reliance on, the Course Manual. Urban Green Council U.S. Green Building Council New York 40 Fulton Street, Suite 802 New York, NY 10038

TRADEMARK GPRO® is a registered trademark of Urban Green Council.

This initiative was made possible by the generous support of the Merck Family Fund and The New York Community Trust.


FOREWORD What is Urban Green Council?

Urban Green Council is the New York Chapter of the U.S. Green Building Council (USGBC). Urban Green's mission is to lead the advancement of sustainability in the urban built environment through education, advocacy, collaboration, and research. Our vision is to see cities that coexist in harmony with their natural environment and contribute to the health and well-being of all. A nonprofit organization established in 2002, Urban Green is supported by contributions from members and sponsors, as well as foundation grants. Our focus is on New York City, and Rockland and Westchester counties. Supported by our in-house experts and a dedicated network of volunteers, our efforts are transforming the metropolitan area and creating models that can be replicated elsewhere.

What is GPRO?

Urban Green Council developed GPRO: Green Professional Building Skills Training, in partnership with the Building Construction Trades Council (BCTC), the Building Trades Employers' Association (BTEA), and the Consortium for Worker Education (CWE). Produced with more than 100 volunteers from local unions, contractors, and design professionals, along with the City University of New York (CUNY) and the USGBC Upstate New York Chapter, this comprehensive, national training program is designed to respond to the building industry's unique needs. It consists of a series of courses and certificate exams that teach the people who build, renovate, and maintain buildings the principles of sustainability combined with trade-specific green construction knowledge. Skilled workers will be positioned to work in accordance with new regulations and to meet the expectations of owners and tenants who want healthier, environmentally sustainable, and energy-efficient homes and offices.





The courses include a prerequisite, Fundamentals of Building Green, and a set of trade-specific courses. Currently, those tradespecific courses consist of Construction Management, Operations & Maintenance Essentials, Electrical Systems, Plumbing, and Mechanical-HVAC. Additional courses will be forthcoming. Applicants will receive a GPRO certificate from Urban Green by passing an exam in their area of expertise. This certificate will demonstrate that an individual understands green building as it applies to his or her trade and will enhance that person's ability to compete for and participate in green jobs.

Who should take this course?

The GPRO training program is designed for experienced building professionals who seek to integrate green practices into the core knowledge of their trade. As such, the program materials and exam cover the "green gap" between standard trade skills and the new knowledge, awareness, and skills required to successfully implement green building. To successfully participate in the Electrical Systems course and pass the certificate exam, individuals should have construction experience in the electrical industry, such as a contractor, electrician, helper, project architect, professional engineer, or commissioning agent.

Urban Green Council Contact Information: Urban Green Council U.S. Green Building Council New York

40 Fulton Street, Suite 802 New York, NY 10038 (212) 514-9385











Sustainability in Electrical Systems


Why Sustainability Matters Electrical Use: Basic Background Power and Energy Consumption

2 4

Sustainability Issues: Electrical Generation Carbon Footprint Site Energy Source Energy Efficiency


Measuring and Analyzing Use Metering Electricity Energy Benchmarking


Required Performance Codes and Standards Green Building Rating Systems and Guidelines


Sustainability and Electrical Work




Lighting: Basic Background Lighting Levels Legal Lighting Requirements Lighting Efficacy Lighting Power Density Color in Lighting


Types of Lamps Incandescent Lamps Halogen Lamps Fluorescent and Compact Fluorescent Lamps Metal Halide Lamps Sodium Vapor Lamps Light-Emitting Diodes


Safe Mercury Disposal for Discharge Lamps


Lighting Controls Basic Controls Sensor Controls


Building-Wide Lighting Controls Temporary Light and Power


Classroom Exercise 1: Lighting Scenarios









Heating and Cooling


Mechanical Components: Basic Background Motors Using Variable Frequency Drives for Greater Control Fans Pumps Component Replacement Plan


Heat Pumps Types of Heat Pumps


HVAC Systems Types of HVAC Systems Electrical Work in Upgrading HVAC Systems


Building Control Systems Types of Building Management and Information Systems


Renewable and Distributed Energy


Energy Generation: Basic Background Utility Grid Radial and Networked Systems Secure Disconnects Selling Energy Back to the Grid

51 52

Cogeneration/Combined Heat and Power Sizing a Cogen Unit Types of Cogeneration Systems Electrical Work and Cogeneration


Fuel Cells Electrical Work and Fuel Cells Costs of Fuel Cells Example Installation


Solar Photovoltaic Power Electrical Generation and PV Systems PV Performance Additional Components of PV Systems Types of PV Systems New PV Technology PV Installer Certification


Wind Power


Tidal Turbines


Electrical Vehicle Charging Systems


Classroom Exercise 2: Basic PV Design







Assuring Building Performance


Commissioning The Importance of Commissioning The Commissioning Process Electrical Work and Commissioning Documentation for Commissioning O&M Training Retro-Commissioning and Continuous Commissioning速


Measurement and Verification (M&V) The Importance of M&V M&V Retrofits M&V and New Construction Standards for M&V Electric Meters for M&V


Classroom Exercise 3: Locating Submeters


Job Management


Whole Building Coordination Inter-Trade Coordination Scheduling Material Submissions Waste Disposal


Site Environmental Quality Air Filters Job-Site Education




Photo and Figure Source Credits




Thank You





i.1: South-facing sloped roofs are one of the easiest places to mount solar photovoltaic panels, seen here on an affordable housing project in San Francisco, CA. Each large square panel will have a peak output of 2,000 to 3,000 watts.




INTRODUCTION Welcome to Urban Green Council's GPRO Electrical Systems course. In this course you will learn about the core practices and new techniques of electrical technology related to sustainable building construction and retrofitting. The material covers a broad spectrum of building systems and sustainability issues along with the basic professional knowledge required to ensure successful building performance. This course is an overview that will show you how to incorporate sustainable practices in your work, while encouraging you to pursue more indepth training in those areas most valuable for your projects and for your career.

đƫ Understand how new technologies for renewable

The course material presumes you have experience in conventional construction practices and consequently addresses only the "green gap," or the information you must know in addition to good practices to successfully undertake a green project. Words listed in bold italics can be found in the glossary at the end of this manual.

đƫ Be responsive to specific green bidding,

As you know from the Fundamentals of Building Green course, the basic goal of sustainability can be stated simply as resource use that "meets the needs of the present without compromising the ability of future generations to meet their own needs." Taking action to realize this goal is what this course is all about. The material for Electrical Systems builds on the information from Fundamentals of Building Green. Upon completion of this course you will: đƫ Understand the environmental and economic

energy sources and distributed generation work and where they are used.

đƫ Understand how measurement, verification, and

benchmarking can help maintain the performance level of a building.

đƫ Understand the electrician's role in the building

commissioning process.

đƫ Recognize opportunities for energy-efficient

installations in the retrofitting of existing buildings. documentation, and specification compliance issues requiring the contractor's attention.

The multiple-choice certificate exam will ensure your grasp of the above objectives, while drawing on content from both this course and the Fundamentals of Building Green course. Upon successfully passing the exam, you will receive a GPRO certificate for the Fundamentals of Building Green and the Electrical Systems courses. Urban Green Council would like to thank you for making this commitment to advancing the electrical industry's capacity to build green. Your participation increases the membership of the growing community of green builders. Together, we will have a significant impact on protecting the environment and creating a healthier, more sustainable world for all.

values of reducing electricity consumption through green and energy-efficient technologies.

đƫ Understand the role of electrical systems and

installation work within the "whole-building" framework of sustainability.

đƫ Be aware of the fundamental differences between

green and conventional electrical products, applications, and work practices.

đƫ Know how to implement efficiencies in lighting and

HVAC (heating, ventilation, and air conditioning) through device selection and installation.






WHY SUSTAINABILITY MATTERS Interest in green and sustainable building practices has increased steadily, both when economic growth has been strong and when project starts have slowed. By the end of 2011, more than 100,000 projects worldwide registered for LEED (Leadership in Energy and Environmental Design) certification, and over 26,000 were certified. What specifically does building green mean for you? Green is where new and better jobs are. Even in tough times, requirements that municipal, college, and other institutional projects be sustainable or LEED certified have meant a steadier supply of jobs in these areas. We can expect this trend to grow in the future, as energy costs and environmental issues are becoming increasingly prominent. Green building offers a more sustainable approach to construction. An important aspect of green building is the whole-building approach, focusing on the integrated nature of all building systems. Figure 1.1 shows some of these integrated systems; those pertaining to electrical issues are labeled in red. Sustainable building practices provide long-term economic benefits through lower operating costs, based largely on reduced energy consumption. Improving controls is key to this reduction, made possible through the use of smarter, more flexible, and data-driven control systems that require more lowvoltage wire and signal cabling. Higher performing lamps also mean



lower loads are met with the least possible energy and resource use. The increased costs for most of these improvements are relatively small, and are paid back in just a few years. A good indoor environment promotes improved health for both workers on the construction project and the occupants who will live, work, learn, or shop there for the life of the building. Green building standards rule out the use of components, paints, glues, and other materials with toxic emissions or waste products, and require that spaces have adequate ventilation for improved air quality. Despite claims of controversy, the evidence for serious climate change is seen daily, and the most necessary response will be drastic reductions in carbon emissions. With training in green building technologies you are not only providing new opportunities for your career, you are also helping to save the Earth for future generations. We will survey sustainable electric technologies in this course. In some cases you may be the one making the purchasing decisions for these technologies, especially in the case of lighting. In other areas, like photovoltaics or cogeneration, others will do the engineering and decision making and you will be faced with the task of implementing their decisions. If you have a better understanding of these systems and related equipment you will be able to do a better and cleaner installation. This course is designed to help you develop that understanding, and we hope you find it interesting and useful.




























Photovoltaic Panels Provide renewable solar electricity Rain Water Harvest Uses water for toilets + garden White Roof or Green Roof Reduces urban heat island effect Sun Control Devices Reduce solar heat gain in summer, direct daylight into room to lower lighting loads Condensing Boiler Reduces energy use for heat + hot water supply Heat Recovery Ventilation or Controlled Exhaust Ventilation Reduces energy use Cogeneration Uses both heat + electric power from local generator High Performance Windows Increase comfort + save energy FSC Wood Flooring Supports sustainable forestry Occupancy + Daylighting Controlled Lighting Reduces energy use, improves indoor environment Low Water/Dual-Flush Toilet Reduces water use Continuous High R-value Insulation Increases comfort + saves energy Recycled Ceiling Tiles Reduce resource use ENERGY STAR Appliances Reduce electrical + water use Low VOC Green Cleaning Products Improve indoor air quality Meters + Submeters Increase awareness of energy + water use Recycling Reduces resource use Access to Mass Transit Reduces energy use Greywater System Recycles water to toilets + garden




1.01: The whole-building approach takes into account all of the complex interactions between various building systems. The systems labeled in red incorporate electrical devices and components.





electrons (see Glossary for exact YOU KNOW? number).DID When one coulomb of charge flows past a point in one second, we say one ampere (A) is flowing. The force driving electric current is called electric potential and is measured in volts (V). When one coulomb of charge is moved across a potential difference of one volt, one joule (J) of work is done. Voltage can be thought of as similar to pressure; it describes how hard the electrons in the supply wire are pressing to get to the return line.

For AC electricity, the voltage and current follow a smooth sine wave (see Figure 1.3) as long as they are not disrupted by "noisy" interference from electronic equipment.

Reducing energy and resource use is at the core of sustainability. To discuss this we need to understand the relationship between power and energy consumption and how electricity use is measured, using watts and kilowatt-hours.

Electric voltage and current are produced either as direct current (DC) or alternating current (AC). For DC, the voltage holds a steady value, and the current moves steadily from the positive voltage terminal to the negative voltage terminal. DC is produced by batteries, solar photovoltaic (PV) panels, and some generators.

CURRENT AND VOLTAGE Electricity is characterized by the flow of current - how many electrons are moving - and how fast they are moving, for instance through a wire. A coulomb (C) of electric charge consists of a specific number of

In AC electricity the voltage and the current fluctuate from positive to negative repeatedly. In the U.S. this occurs at 60 times per second, and at much higher frequencies inside some electronic equipment. This is referred to as 60 hertz (Hz).

AC electricity in a building is commonly carried by two wires: a neutral wire whose voltage is always close to ground, and a hot wire whose voltage swings up and down, as shown in Figure 1.3. For higher voltages and longer distance transmission, three wires are often used and the circuit is described as three-phase power. In these circuits there is a voltage between each pair of wires that can provide useful power to loads. The advantage of this complex system is that it allows more power to be carried over a given amount of wire. We will not need to analyze these systems in this course, but we will refer to them from time to time.

ELECTRICAL USE: BASIC BACKGROUND Understanding sustainability in electrical systems involves quite a bit of technical knowledge. As electricians you will know much of this information already, but we will cover the basics here to make sure everyone is up to speed. Even if this material is familiar, it may be helpful to review as these concepts will be referenced throughout the course.


The big advantage of AC electricity, and the reason it is found everywhere, is that it is relatively easy to convert low voltage to high voltage and then back again in transformers. This permits longdistance transmission of electric power − a key to modern life.


Instantaneous Voltage (volts)

150 100 50 0 -50 -100 -150 -200





Time (seconds) AC Volts

1.2: High voltage power lines bring electricity from distant power plants to cities.



Equivalent DC Volts

1.3: AC electricity oscillates from positive to negative in a sine wave pattern, while DC remains at a constant value.



1.4: Satellite imagery of the U.S. before the 2003 Northeast Blackout.

ELECTRIC POWER Electricity use is measured as both power and energy, and although closely related, they are not the same. Power is the rate at which work is being done and is measured in watts (W). 1 kilowatt (kW) = 1,000 W, and 1 megawatt (MW) = 1,000 kW = 1,000,000 W Power tells you how quickly work is being done, and is similar to a horsepower rating that tells you how quickly an engine can propel a car up a hill. Watts are useful for measuring the power consumption of small devices and appliances (such as a 35 W lamp), kilowatts are useful for large appliances or total usage in a small apartment (a 2 kW electric room heater), and megawatts are used for sizing electric delivery systems or power plants. Power plants at U.S. electric utilities range in size from 100 MW up to large coal or nuclear installations with a capacity of 1,000 MW or more. The peak power to be consumed in an appliance or building determines how large the wires must be to safely supply the needed electric power. URBAN GREEN COUNCIL

1.5: Satellite imagery of the U.S. during the 2003 Northeast Blackout.

ELECTRIC ENERGY Electric energy consumption is the amount of work done by electricity over a particular amount of time, and is measured in kilowatt-hours (kWh), as seen on your electric bill. If 1 kilowatt (1,000 W) of electric power is used for 1 hour, 1.0 kWh of electric energy is consumed. Similarly, if 100 watts (100 W) of electric power are used for 10 hours, 1,000 watt-hours (Wh) or 1.0 kWh is consumed. Remember, a kilowatt measures power, which is a rate (like gallons per minute). A kilowatt-hour is an amount of electrical work done by electricity (like a gallon of water). Expressed in terms of watt-hours: 1 kWh = 1,000 Wh, and 1 MWh = 1,000 kWh = 1,000,000 Wh. In the 1970s, refrigerators used more than 2,000 kWh per year; today's models can use less than 500 kWh per year. For reference, a 100-unit multi-family building (including tenant use) might consume 500,000 kWh per year, which can also be written as 500 MWh.

ELECTRICAL GRID DEMAND Peak demand or peak load are terms used interchangeably to describe the maximum power, measured in kilowatts (kW, not kWh), drawn during a time period, usually 1 month. In many utility districts, peak monthly demand for billing purposes will be the highest value of the power drawn through the meter during the month. On a larger scale, at any given instant, the total power demand on an electric utility will be the sum of the demands from all the equipment in all the buildings in its territory. The peak load on the grid is a key factor for electric utility operations. For example, the peak demand in all of New York City for 2005 was 11,400 MW, which occurred on a hot afternoon in July when many air conditioners were running. The peak load for N.Y.C. is projected to rise to 14,700 MW by 2030. Since peak load is measured when the electric grid is under the greatest strain and most likely to overload and produce a blackout, great effort is put into finding ways to reduce peak loads. Currently, larger electric customers pay a "demand charge" to the electric utility based on their peak demand each month. We will review




some strategies in this course that will help to reduce these demand charges to save both energy and costs.

SUSTAINABILITY ISSUES: ELECTRICAL GENERATION A key priority in sustainability is climate change, driven by emissions of carbon dioxide (CO2) and other greenhouse gases such as methane. Greenhouse gas emissions are usually measured in pounds of CO2 equivalent (CO2e). This refers to the amount of CO2 that would have to be emitted to equal the global warming potential of all greenhouse gases (CO2 plus the other greenhouse gases). Using this measure is simpler than keeping lists of all the different gases.

CARBON FOOTPRINT The carbon footprint from electricity production varies dramatically depending on the fuel used. A coal-fired power plant emits about two pounds of CO2 equivalent per kilowatt-hour (2 lbs CO2e/kWh). A natural gas-fired plant is in the range of 1.5 lbs CO2e/kWh. Nuclear, hydro power, and renewables such as wind and solar have much smaller carbon footprints, but they are not zero due to their manufacture and maintenance. For example, hydro power produces about 0.03 lbs CO2e/kWh. Averaging the different methods we use to produce electricity in the U.S., the carbon footprint for electrical generation in the U.S. is about 1.6 lbs CO2e/kWh.

11,400 Btu Produces


Wasted Thermal Energy

1 kWh (3,413 Btu)


1.6: Due to low generation efficiency, thermal power plants use three units of source energy to produce one unit of electric energy.

SITE ENERGY The amount of energy delivered to a building is described as the site energy (SiteE). The site energy is the total amount of the fuel used directly in the building (usually natural gas or fuel oil) added to the amount of electricity delivered to the building. The fuel used directly in the building is usually measured in heat units, or British thermal units (Btus). To add these amounts together we need to

use the same units, so we must first convert the electricity consumed (measured in kilowatt-hours) to heat units at a rate of 3,413 Btu/kWh. To find the total site energy in a building, the fuel use (in Btu) is added to the electric use, which is the kilowatt-hours consumed multiplied by 3,413 Btu/kWh (see Example 1).

EXAMPLE 1: A building consumes 500,000 ft3 of gas and 200,000 kWh of electricity per year. Gas energy content is 1,030 Btu/ft3. Electric energy content is 3,413 Btu/kWh. What is the site energy? ANSWER: The site energy is the energy content of the gas and electricity used: SiteE = (500,000 ft3/year x 1,030 Btu/ft3) + (200,000 kWh/year x 3,413 Btu/kWh) &


5 1 5 ,000,000 Btu/year + 682,600,000 Btu/year 1,1 97, 600,000 Btu/year or 1,198 MMBtu/year (each "M" means 1,000, so "MM" means one million)




SOURCE ENERGY The amount of useful electrical energy actually delivered to a building is typically about one-third of the amount of energy used to generate it! The other two-thirds are lost mainly in wasted heat at the generating plant, with a small amount of energy also lost in transmission (see Figure 1.6). To account for this large amount of lost energy when making comparisons in energy use between buildings using both fuel and electricity, we use a concept called source energy (SourceE). The amount of energy in the fuel used to generate the electricity is called the source energy. Figuring out a building's source energy use gives us a better indication of its overall environmental impact by measuring the amount of fossil fuels burned to produce the energy used at the building. Figure 1.7 compares the source energy use of various building activities. This analysis gives us a good idea of the amount of CO2 emitted from each of these activities. The United States Environmental Protection Agency (U.S. EPA) has developed a national average value for the conversion of electric energy to source energy of 11,400 Btu/kWh. That's a little over three times the 3,413 Btu/kWh of energy calculated for site energy use. See Example 2 on page 8, which shows how source energy is calculated. We will see how to reduce these losses in the section on cogeneration in Chapter 4. Electric power is generated using a wide variety of fuels and other resources. Figure 1.8 shows the amounts of electricity produced from different fuels and sources in the U.S. The carbon footprint of electricity consumption depends on the fuel used, which will vary from one region of the country to another. With 44.9% of U.S. electrical generation coming from coal, a large quantity of carbon is released into the air from coal-powered electrical generation. Another issue with coal use is that mercury is contained in the coal being burned; the U.S.


Uncertainty 7.2%

Space Cooling 13.2%

Other 13.7%

Cooking 2.1%

Space Heating 20.7%

Wet Cleaning 2.5% Computers 3.0% Ventilation 4.0%

Water Heating 9.1%

Electronics 4.7% Refrigeration 6.5%

Lighting 13.4%

1.7: 2010 Source energy use in U.S. buildings - these numbers account for the fuel used to generate the electricity used in the buildings.

Nuclear 20.3%

Natural Gas 23.4%

Conventional Hydroelectric 6.9% Other Renewables 3.6% Petroleum 1.0%

Coal 44.9%

1.8: Amount of U.S. electricity generation by type of fuel or energy in 2009.




EXAMPLE 2: What is the source energy of the building in Example 1? The conversion value of the electric energy to source energy is 11,400 Btu/kWh. ANSWER: The source energy is the fuel used at the power plant added to the converted value of the electrical energy: SourceE = (500,000 ft3/year x 1,030 Btu/ft3) + (200,000 kWh/year x 11,400 Btu/kWh) '& 515,000,000 Btu/year + 2,280,000,000 Btu/year '& 2,795,000,000 Btu/year or 2,795 MMBtu/year

EPA has estimated that half of all mercury emissions in the U.S. are a result of coal-fired electric power production. In early 2012 the U.S. EPA issued regulations to reduce mercury emissions from power plants by 90% over the next five years.

EFFICIENCY One way to lower emissions and our environmental and carbon footprints would be to return to a pre-industrial, agricultural economy. This is simply not possible given the billions of people on Earth, or even the millions in the U.S. We must instead use our technology to accomplish much more with much smaller inputs of energy and materials. Electricity will be key in this move to increased efficiency and electricians will find many opportunities in the construction industry, including areas where they have traditionally had a lesser role such as heating, ventilation, and air conditioning (HVAC). For the green electrician, sustainability means efficiency. But what do we mean by efficiency? In the broadest sense, for a given product or service we look at different processes that can create the desired product or service. The less the process needs in terms of inputs, including energy and raw materials, the more efficient it is:

We will be looking at situations where the desired product is some condition in a building, such as pleasant temperatures and humidity, or levels of lighting appropriate to a task; the input energy will be electricity or perhaps the fuel used to generate electricity when determining source energy. Our goal will be to provide the same or better services more efficiently with less electricity consumption. Let's start by looking at current source energy use in U.S. buildings, based on data available from the U.S. Department of Energy (U.S. DOE), which we see in Figure 1.7. Of these categories, space heating and hot water heating consume about 22% of the total, though they are primarily derived from fuels and don't involve much electricity. All the other categories in the remaining 78% use electricity. The key factor to keep in mind is that we can provide the same services with substantially smaller inputs if more efficient equipment is installed and used properly. Throughout this course we will look at specific ways this can be done.

Efficiency = Desired Product Input Energy and Materials 8




MEASURING AND ANALYZING USE You can't know how much energy you are using if you don't measure it! This concept has been applied to electric power and energy practices since the 19th century, as those who generate electric power can only charge for what is actually consumed. We'll cover some of the technical aspects of meters in Chapter 5, but first we must clarify what electric meters measure, and how their location determines who is paying for the power. Once we determine how much energy we are using, not only can we start to compare a building's annual fuel usage to other years, but also to similar buildings. This concept is called benchmarking, an important component of any energy management program, especially when sustainability is a primary focus.

METERING ELECTRICITY Electrical meters measure energy and power. Energy, expressed in kilowatt-hours (kWh), is measured over a time period, usually 1 month for utility billing. Customers currently pay $0.07-$0.25 per kWh in the U.S. This wide variation depends on location and billing structure.

1.9: This digital electric meter measures kilowatt-hours consumed.


Power can be measured only at an instant ("the building is currently drawing 15.3 kW"), but what the utility wants to know is the maximum power drawn during a particular billing period, the peak demand. This is measured using a demand meter (also known as an interval meter) that can retain information about the peak power until it is read. For larger customers, in addition to energy charges there will be a demand charge of several dollars per kW of peak demand during the billing period. Meters can be arranged several different ways. For single-family homes or single-purpose commercial or industrial buildings, there will be one utility meter on the building for the one customer inside the building. This is called direct metering. For larger buildings with multiple tenants or residents, the situation is more complex. In multi-family buildings, each apartment may have its own utility account and meter. This is again direct metering, where the utility bills the tenant directly. This arrangement can also occur in multitenant commercial buildings, but is less common. There can also be a master meter for the whole building, where the utility installs a single utility meter to record consumption of the entire building. The owner receives one bill for the account, and then charges the tenants separately. This can be done in two ways. First, the owner can charge a fixed amount for electric service. In this case, there is no way to know how much energy and power each tenant is using, and thus there is no motivation for the tenants to conserve energy. This is a very inefficient system, and building codes and efficiency standards are increasingly requiring that all spaces be individually metered. The other way building owners can charge for electrical use is through submeters, which are individual meters for tenants' spaces. The owner can bill their tenants monthly for their usage based on meter readings. This is far better from a sustainability point of view, since a

tenant who installs an energy-saving system will be able to see these lower electric bills. The different metering arrangements can be reflected in different wiring systems in buildings. Spaces that are either directly metered or submetered must have all their power pass through a single load center where the meter and circuit breakers can be found. Installation of submeters in buildings with master meters is constrained by the existing locations of circuit breakers, which may or may not correspond to tenant spaces.

ENERGY BENCHMARKING When benchmarking energy use, the baseline of energy use over at least a full-year period is established to compare with future annual patterns of consumption for the building. The usage is also compared to buildings of similar size and type. By tracking, monitoring, and assessing energy use, the process of benchmarking identifies potential savings and prioritizes necessary improvements. Benchmarking is not just for energy use; water use can also be assessed. The most common measure for energy benchmarking is the energy use intensity (EUI). This represents the total fuel burned plus the electricity consumed on a per-square-foot basis. This can be calculated with either site energy or source energy. We found the site and source energy use for our sample building in Examples 1 & 2; the site EUI and source EUI for this building are calculated in Examples 3 & 4 on page 10. Benchmarking is made easier by Portfolio Manager, a software tool from the U.S. DOE that allows building owners, operators, and engineers to assess whole-building energy and water consumption, and track changes in energy, water, greenhouse gas emissions, and cost over time. Information such as building characteristics, operational characteristics, and energy or water data is used to make these assessments.




EXAMPLE 3: What is the site EUI of the building from Examples 1 & 2? The useful floor area is 23,000 sf. ANSWER: We found the site energy to be 1,198 MMBtu/year, so: Site EUI = 1,197,600,000 Btu/year = 52,070 Btu/sf/year 23,000 sf This is an average value for a multi-family residential building.

EXAMPLE 4: What is the source EUI of the building? The useful floor area is 23,000 sf. ANSWER: We found the source energy to be 2,795 MMBtu/year, so: Source EUI = 2,795,000,000 Btu/year = 121,522 Btu/sf/year 23,000 sf

REQUIRED PERFORMANCE CODES AND STANDARDS Traditionally, building codes have been concerned with health and safety — making sure that the need to minimize costs didn't lead to unsafe buildings. Fire escapes and fire stairs are an obvious example; they cost money, but people would be put at unnecessary risk without them. All buildings must have fireproof means of egress, as well as many other features dedicated to safety. These safety-based codes tend to define minimum characteristics for the item under consideration. Steel support structures must be designed for specific minimum loads. Wires, transformers, and other electrical equipment must have specified minimum gauges and capacities depending on their function and expected loading. This sometimes leads to systems being overdesigned, at perhaps unnecessary expense, but the general attitude is "better safe than sorry."



For electrical work, the basic health and safety code is the National Electrical Code (NEC), or NFPA 70, prepared by the National Fire Protection Association (NFPA). The NEC is at the basis of all electrical work in the U.S. It is very important to remember that as we strive for greater efficiency, we must always stay within its requirements.

adhering to voluntary rating systems. In either case, energy and wateruse restrictions tend to put upper limits on the capacity of equipment, instead of minimums on performance that result from traditional codes. There are two standards or codes that are also independently prepared, widely adopted, and aimed at lowering energy consumption. The first is prepared by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), along with the American National Standards Institute (ANSI) and the Illuminating Engineering Society (IES), called ANSI/ASHRAE/ IES Standard 90.1–2010, Energy Standard for Buildings Except LowRise Residential Buildings, referred to as Standard 90.1. The standard is reviewed and revised every three years. Recently it has been made significantly more rigorous, aiming for extremely efficient buildings as standard construction by 2030. In 2011 the U.S. DOE established Standard 90.1 as the commercial building reference standard for all state building energy codes. We will discuss some of its requirements in later chapters.

The other independent code aimed at lowering energy consumption is the International Energy Conservation Code (IECC) prepared by the International Code Council (ICC). The IECC is often adopted as The NEC, like most codes, is prepared a state or local energy code in along by an independent group and has with Standard 90.1. The IECC actually no legal standing by itself. Rather, accepts compliance with Standard it must be adopted as the local 90.1 as equivalent to compliance with electrical code by a municipality or the IECC for high-rise residential and state. The adopting government will all commercial buildings. often add various local adaptations responding to local conditions, such Because of demand for a greener as the numerous very large high-rise code aimed at a higher level of buildings in New York City. sustainability, ANSI/ASHRAE/ USGBC/IES Standard 189.1-2009, More recently, new building Standard for the Design of Highcodes and code restrictions have Performance Green Buildings was been developed to help curb our developed. Compliance with this enormous appetite for energy and document will result in a building water. The most common example that consumes far less energy is energy codes, though water and water than conventional efficiency measures are included in construction, but at a somewhat many plumbing codes. In addition higher initial cost. No municipality to these new code requirements, many developers and owners are also



ANSI/ASHRAE/IES Standard 90.1-2010 (Supersedes ANSI/ASHRAE/IESNA Standard 90.1-2007) Includes ANSI/ASHRAE/IES Addenda listed in Appendix F

ASHRAE STANDARD Energy Standard for Buildings Except Low-Rise Residential Buildings I-P Edition See Appendix F for approval dates by the ASHRAE Standards Committee, the ASHRAE Board of Directors, the IES Board of Directors, and the American National Standards Institute. This standard is under continuous maintenance by a Standing Standard Project Committee (SSPC) for which the Standards Committee has established a documented program for regular publication of addenda or revisions, including procedures for timely, documented, consensus action on requests for change to any part of the standard. The change submittal form, instructions, and deadlines may be obtained in electronic form from the ASHRAE Web site ( or in paper form from the Manager of Standards. The latest edition of an ASHRAE Standard may be purchased from the ASHRAE Web site ( or from ASHRAE Customer Service, 1791 Tullie Circle, NE, Atlanta, GA 30329-2305. E-mail: Fax: 404321-5478. Telephone: 404-636-8400 (worldwide), or toll free 1-800-527-4723 (for orders in US and Canada). For reprint permission, go to Š Copyright 2010 American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. ISSN 1041-2336

Jointly sponsored by

Illuminating Engineering Society of North America

American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. 1791 Tullie Circle NE, Atlanta, GA 30329

1.10: The IECC is the basis of many statewide energy codes.

1.11: Standard 90.1 is an alternative energy code for commercial buildings referenced in the IECC.

1.12: ASHRAE pushes the envelope further with the more rigorous Standard 189.1 for sustainable buildings.

has yet adopted Standard 189.1 as its only code standard. Certain governmental projects now use it as a voluntary standard.

These were presented in some detail in Fundamentals of Building Green, and here we will focus on their impact on electrical work.

The ICC has undertaken a similar effort, which will result in the International Green Construction Code (IgCC) when it is concluded in 2012. It will incorporate Standard 189.1 as an alternative compliance path within itself, much as the IECC incorporates Standard 90.1.

The U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) rating system establishes criteria for minimizing the environmental footprint of buildings and neighborhoods. On LEED jobs there is a much greater emphasis on better lighting systems, efficient HVAC, and careful selection of motors. Because the Sustainability Team must file extensive documentation, you will have to retain careful records of purchases showing exact product model numbers. Sometimes, you will need to provide auxiliary documents showing that an efficiency standard has been met, or a product is free of noxious chemicals. Because LEED certification involves a significant effort to file the necessary documentation, it is not often applied to smaller buildings, though LEED for Homes is a new system aimed at residential buildings three stories tall or less.

voluntary design guideline similar to LEED for Homes, but aimed at energy efficient products and practices. Verification of the ENERGY STAR rating is carried out by a trained professional called a "Rater." Electricians are normally responsible for less documentation and verification for ENERGY STAR projects than for LEED projects.

Over the years, the federal government has established various standards for the efficiency of appliances and other equipment that must be met if a device is to be sold in the U.S. To go further, and to recognize outstanding performance, the U.S. EPA and DOE created the ENERGY STAR label, which is granted to products in the upper range of performance in their category. ENERGY STAR equipment is available in a wide range of categories: lighting, HVAC, appliances, and residential and office equipment.

GREEN BUILDING RATING SYSTEMS AND GUIDELINES There are several rating systems currently in use for sustainable building design and performance.


There is also an ENERGY STAR rating available for existing buildings, obtained by submitting the building's operational statistics (fuel and electric use, etc.) to Portfolio Manager. To be eligible for this ENERGY STAR rating the existing building must perform in the top 25% of buildings in their class for lowest source energy use.

The U.S. EPA and DOE have established the ENERGY STAR for New Homes Program for the construction of residential buildings of three stories or less. This is a




SUSTAINABILITY AND ELECTRICAL WORK In the remainder of this course, we will examine a wide range of technologies where the drive toward sustainable construction emphasizes new and more efficient approaches. Better lighting controls, improved lighting fixtures, variable speed drives on motors, and improved HVAC equipment are all aimed at cutting consumption. Careful selection of materials will lead to the use of low VOC sealants and adhesives. Increased recycling of construction waste will allow our limited resources to go further.

1.13: The ICC is working on defining a standard for sustainable buildings in the International Green Construction Code.

As we survey this array of new and sometimes unfamiliar technologies, it will be important to remember that even if they are currently not widely used, these sustainable technologies will soon be used more frequently in all sectors of the construction industry.

1.14: The U.S. Green Building Council developed the LEED certification process.

With this material under your belt, you'll be ready when the building owner says, "Let's go green!"

1.15: The ENERGY STAR logo certifies that a product, home, or building uses significantly less energy than typical.

1 TEST YOURSELF: 1. What are the benefits of sustainability in green

building design?

2. What is peak demand and under what

circumstances is it most likely to occur?

3. What is the difference between site energy

and source energy, and how are they related to electricity usage?

4. What are the codes and standards related to green

building and what are their functions?

5. What is ENERGY STAR and how does it relate to

the LEED rating system?




Sample Chapter: Electrical Systems  
Sample Chapter: Electrical Systems  

GPRO Electrical Systems teaches sustainable construction practices to electricians and workers in the electrical industry.