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Mechanical

G|PRO Green Professional Building Skills Training


COPYRIGHT

DISCLAIMER

Copyright © 2014 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 Mechanical, 2014 edition, v1.5. 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 20 Broad Street, Suite 709 New York, NY 10005

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

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This initiative was made possible by the generous support and expertise of the United Association International Training Fund.

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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 advance sustainability of urban buildings through education, advocacy, 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 funded by contributions from foundations, its members, and corporate sponsors. Our focus is on New York City, and Rockland and Westchester counties. Our in-house experts and a dedicated network of volunteers are helping to transform the built environment in New York City with models that can be replicated in urban centers nationwide.

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, international 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.

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FOREWORD

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. 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 Mechanical course and pass the certificate exam, individuals should have construction experience such as an HVAC installer, sheetmetal workers, pipefitter, mechanical insulator, project architect, professional engineer, or commissioning authority.

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

www.gpro.org gpro@urbangreencouncil.org

20 Broad Street, Suite 709 New York, NY 10005 (212) 514-9385 www.urbangreencouncil.org

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CONTENTS Introduction

1

1:

Sustainability and Mechanical Systems Why Sustainability Matters How Green Mechanical Systems Are Different Whole-Building Approach Integrated Design Process The Relationship Between Sustainability And Proper Installation Performance Classroom Exercise 1

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2:

Building Science Basics Energy, Heat, and Temperature Heat Transfer Phases of Matter Three Fluids Heat Exchangers Fans, Pumps, Compressors…and the Motors that Drive Them Vapor Compression Cycle The Building Envelope Climate Zones “Diminishing Returns”

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3:

Indoor Air Quality & Ventilation Good Indoor Air Quality and Why It Matters IAQ Problems Ventilation Ventilation Systems Construction Indoor Air Quality Plan

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4:

Cooling Systems Introduction Heat Exchange Configurations Standard Cooling System Types and Issues Large Central Chillers Economizers Distribution Efficiency Ratings Sustainable Cooling Technologies Refrigerant Management Beyond Vapor Compression

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5:

Heating Systems Introduction Indirect vs. Direct Heating Heat Distribution Systems Heat Sources Heat Pumps Solar Water Heating Solar Space Heat Cogeneration

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CONTENTS

6:

Insulation Insulation is Too Often Overlooked in Buildings Benefits of Insulation Who is Responsible for Proper Insulation? Types of Insulation Installation, Maintenance, and Safety Insulation is Essential

80

7:

Instrumention & Controls for HVAC Controls are More Connected Early HVAC Controls Levels of Building Control Systems Installation Issues

85

8:

Testing, Adjusting & Balancing Who Does What? Testing Balancing Adjusting Preparing for TAB Importance of TAB to Cx

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9:

Commissioning & Energy Performance Commissioning Measurement & Verification

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10:

Corrective, Preventive & Predictive Maintenance Types of Maintenance Who is Involved? Training Process Techniques

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11:

Green Construction Management Project Management Critical to Success of Green Buildings Timeline Considerations on High-Performing Buildings Temporary Heat & A/C Systems Air Sealing Ducts in New Construction Site Environmental Quality Compliance With the Construction Indoor Air Quality Plan (CIAQ)

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12:

Existing Buildings The Challenge Renovation Retrofit Energy Audits Common Pitfalls

115

Conclusion

125

Additional Resources

126

Photo & Figure Source Credits

127

Glossary

129

Appendix A

136

Appendix B

139

Thank You

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i.1: Riverhouse (New York City): LEED Gold residential building uses triple-glazed windows for lower heating loads and ground-source heat pumps to meet them efficiently.

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INTRODUCTION Welcome to Urban Green Council’s GPRO Mechanical course. This is the second step in our training and certification program for mechanical professionals. Building upon the core information about sustainability and construction provided in the Fundamentals of Building Green course, in this program you will learn more specifically about the new ways a mechanical professional thinks and works on a green job. Humans can survive in a wide range of environments, but we prefer to be comfortable, in any weather. Heating, ventilating, air conditioning, and refrigeration (HVACR) are the technologies that provide this comfort and convenience inside our buildings. The level of comfort we can achieve is remarkable: fresh, clean air, comfortable temperatures, rooms that are not too dry and not too moist, and reliable food storage. Throughout the 20th century, HVACR equipment continued to be improved, and by the 1990s it was possible to create almost completely comfortable indoor environments. This is the equipment you have studied since you started in HVACR, and we’ll assume you know all about how it works. Just when it looked like HVACR had been (almost) perfected, another problem showed up: the amount and type of energy people use to maintain living standards is more than the planet can tolerate. Now, not only does HVACR equipment have to provide perfectly conditioned air, but it must do that using much less energy. First, this means making building envelopes as tight, well-insulated, and carefully windowed as possible, to minimize the heating and cooling loads. This isn’t a job for HVACR technicians, but it changes your job in several ways: we can no longer count on leaks and windows to supply fresh air, we must use mechanical ventilation. Second, we must make all HVACR equipment use fuel and electricity as efficiently as possible. Third, we have to examine standard types of equipment to see if they are still a good choice. In one example, we’ll see that today's sustainable designs will move only the air required for ventilation around a building, using refrigerants or hot and cold water to feed room air handlers and chilled beams to distribute the heating and cooling. Finally, we’ll see that several new or rare technologies are becoming common, such as heat and energy recovery ventilation. GPRO Mechanical will offer an introduction to the concerns, understandings, and new HVACR practices that are changing the way we provide comfort in our buildings. These changes are moving us to a world that will be sustainable over many generations, while still

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providing expected levels of comfort. Upon completion of this course, you will understand: đƫ How energy efficient mechanical systems are a core part of green building design đƫ How sustainability requirements and LEED credits affect mechanical trade work đƫ The basic background and components that make up the foundation of all mechanical systems đƫ The HVAC system's critical role in providing healthy indoor air for occupants đƫ New technologies and approaches for reducing energy use in cooling systems đƫ New, energy-efficient technologies and approaches for heating systems, and how waste heat can be reused đƫ How mechanical insulation saves energy and increases the efficiency of mechanical equipment đƫ How controls are necessary to attain the maximum efficiency from new, complex HVAC systems đƫ Your role in testing, adjusting, and balancing, to optimize the operation of mechanical systems đƫ The mechanical trade's role in the building commissioning process đƫ How ongoing maintenance ensures systems continue to function properly, optimizing energy performance over its lifespan đƫ How to comply with timeline, cost, and documentation issues on green projects, especially in connection with LEED đƫ Recognize opportunities for energy-efficient products and practices in the retrofitting of existing buildings The multiple-choice certificate exam will ensure your grasp of the objectives listed above, while drawing on content from both this course and Fundamentals. To prepare, we recommend studying both manuals and reviewing the "Test Yourself" questions at the end of each chapter. Urban Green would like to thank you for making this commitment to advancing the building industry’s capacity to operate and maintain green buildings. Your participation increases the membership of the growing community of green building professionals. Together, we will have a significant impact on protecting the environment and creating a healthier, more sustainable world for all.

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SUSTAINABILITY AND MECHANICAL SYSTEMS

WHY SUSTAINABILITY MATTERS Sustainable building practices are becoming more common. As the construction industry responds to increased concerns about the environmental and health impacts of buildings, and as standards for comfort become more rigorous, green increasingly means good. After all, when buildings are designed, built, and operated in a sustainable manner, they use less of our natural resources, reduce environmental pollution, improve workers’ and occupants’ health, and benefit the economy. A building’s mechanical systems are key. It keeps occupants warm in the winter and cool in the summer, ventilates with outside air, and removes indoor pollutants. To do all this, it consumes about two-thirds as much energy as all other building systems combined. Sustainable mechanical systems that address efficiency, comfort, and health are therefore at the core of green buildings. Transitioning to such systems will provide energy and water savings for building owners, increase durability of buildings and HVAC systems, and keep occupants more comfortable. Mechanical professionals who can make this transition will be key members of the green building team.

1.1: Existing building renovation and new building construction offer a significant number of green job opportunities for individuals in the mechanical trades.

ECONOMY

Interest in sustainable building practices has steadily increased over the past decade. One of the main reasons for this is the savings that energy-efficient mechanical systems provide. Developers, owners, and operators want higher performing buildings that save money, and sustainable mechanical systems In Fundamentals of Building Green, deliver. HVAC is projected to be a you learned about the four benefits leading sector in the green building of green building: a healthy economy, industry, growing from $3.1 billion to more desirable jobs, improved worker $6.4 billion by 2017. and occupant health, and decreased environmental impact. Sustainable mechanical systems further these objectives in the following ways:

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JOBS New job opportunities abound for people with green building skills (see Photo 1.1). The federal government and many local governments, institutions, and private companies now have energy efficiency standards or requirements for LEED certification. This creates a high demand for professionals who are knowledgeable about sustainable mechanical systems. For example, the Bureau of Labor Statistics projects jobs for HVAC mechanics and installers in the U.S. to grow 21% from 2012 to 2022. In Canada, the number of HVAC technicians is projected to increase significantly.

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1.2: Energy recovery ventilators minimize the need for input energy by transferring heat between the space to temper outside air. In this way, they increase the efficiency of energy use significantly.

HEALTH Clean air on construction sites protects workers’ health. Likewise, fresh indoor air protects occupants who live, work, learn, or shop in the building. Good indoor air quality is in large part determined by a wellfunctioning and efficient mechanical system. ENVIRONMENT Reducing the impact of climate change requires reducing fuel consumption, electricity use, and carbon emissions. A building’s mechanical systems use much of its energy and produce a large portion of its carbon emissions. By adopting green practices and learning about green building technologies, you are helping to slow climate change, protect natural resources, and provide a more sustainable future. It’s important to understand that this new emphasis on sustainability is a widespread, global change made as a result of environmental concern. Governments, businesses, and individuals are leading the movement to improve the built environment. The techniques presented in the remainder of this course will be useful for complying with current green building rating systems, as well as with new, more stringent efforts that are bound to emerge as concern about energy use grows.

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HOW GREEN MECHANICAL SYSTEMS ARE DIFFERENT Maintaining occupant comfort and health while reducing energy use and environmental impacts is at the core of sustainable mechanical systems. Mechanical systems include devices that control a building’s temperature, humidity, ventilation, and air quality — all of which present complex challenges. Sustainable buildings may also incorporate solar heat, cogeneration, heat recovery, and demand control ventilation. Although green mechanical systems may be more complex than traditional systems, they present more opportunities for improving performance (see Photo 1.2). One can wring more efficiency out of these systems by installing thicker insulation on more components, installing sensors to better control fluid flow, recovering otherwise wasted heat, and replacing energywasting single-speed drives with variable-speed alternatives. To minimize impact while maintaining current standards of comfort, health, and safety, these complex systems require installers and contractors to pay more attention to detail than ever. For example, sensors must be wired to the correct warning light, controls must turn the right motor on and off, and the temperature scale

of the building management system must match the scale of the sensors. Green mechanical systems are less tolerant of errors; in order to spot and correct problems, therefore, you must have a “big picture” understanding of how they work. That holistic picture is what we hope to provide in your GPRO training. To reduce the load in low-energy structures, the first step is perfecting the building’s walls, roof, windows, and doors — otherwise known as the “envelope.” Even a building with the tightest envelope, however, needs mechanical ventilation, heating, and cooling. Irrespective of the building envelope, therefore, the HVAC equipment must be as efficient as possible in order to maximize sustainability. This is more complex than it sounds, as smaller loads are also more variable. As a result, the equipment must not only operate efficiently, but also be able to respond to rapidly changing demands. For instance, if a room has a large, south-facing window, the heating load may vary dramatically as the sun moves through the sky or is obscured by a cloud. Comfort will require that the heating system shut down as the sun warms the room, and then start up if the room starts to cool, using the least possible amount of energy as it does so.

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A B C D

A E

C B

F

D

G

F

E

H

G

I J

K L

H I

M

K

J

N

L

O

M P

O

N

P

Q R

Q R

S

Solar Thermal Provide renewable solar water heating 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

P POTABLE WATER

S

BLACK WATER

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

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WHOLE-BUILDING APPROACH

INTEGRATED DESIGN PROCESS

One of the most important green building concepts is the “wholebuilding approach,” a method of thinking about buildings as integrated systems that depend on one another, rather than discrete systems that operate individually. In well-designed, high-performing buildings, systems work together to provide a comfortable, healthy environment as efficiently as possible (see Figure 1.3).

Green building is about more than making sure building systems work together; it is also about teamwork, as builders and designers must involve the whole team from the beginning of the project. This is called an integrated design process. Successful green buildings can only be achieved if the entire team, from design through operations, works together to achieve a sustainable goal. The integrated design process facilitates the whole-building approach, reduces errors, improves relationships, and allows the design team to identify smarter design options.

For example: đƫ If a building uses high-efficiency light bulbs, which don’t give off as much heat as incandescent or halogen bulbs, the building uses less energy for both lighting and cooling, but will need a little more energy for heating. đƫ In a building with a tight envelope, occupants are more comfortable because walls and windows are warmer; there are fewer drafts; heating and cooling loads are reduced; and ventilation can be monitored, controlled, and tempered. đƫ In green buildings, better indoor air quality may require more outside air; the HVAC system will be designed to accommodate the additional loads as efficiently as possible, including, for example, heat recovery ventilation. To achieve whole-building harmony, all team members working on the design, construction, and operation of a sustainable building must be aware of the ways the system they are working on can interact with all the other systems in the building.

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For example, the interior designer may suggest a lighter paint color for a wall. The electrical engineer then recognizes the lighter tone will reflect daylight better and reduce the lighting levels needed in the room. Because less cooling may be needed, the mechanical engineer can then revisit the size of the mechanical system. The resources freed up by purchasing less lighting and a smaller mechanical system can then be invested elsewhere in the project.

THE RELATIONSHIP BETWEEN SUSTAINABILITY AND PROPER INSTALLATION In green buildings, errors during installation can compromise the efficiency and even the operability of HVAC and other building systems. Green building rating systems and the newest version of the International Energy Conservation Code require commissioning of building systems to minimize these errors. For the HVAC contractor, this means more planning and documentation up front, as installers now must perform new and possibly unfamiliar tasks associated with the commissioning process. However, the installer will also benefit from fewer return trips because of errors, and fewer delays because the commissioning process will find more design errors earlier on in the project.

PERFORMANCE Building designers must ask themselves two questions about building performance: First, does the building provide a healthy, comfortable environment, with all the necessary services for its occupants? Second, what is the environmental impact of the construction and building operation to meet those requirements? Even when the building is constructed exactly in accordance with the owner’s requirements, the building operator and residents will play a large role in determining how much energy the building actually uses. In this course, we will emphasize the technologies and components that HVAC workers can use to improve building performance.

HOW MUCH ENERGY DO BUILDINGS USE? In 2012, buildings used about 40% of all energy in the United States (48% if you include industrial buildings), and 50% of all energy in Canada. Within buildings, heating, ventilation, and air conditioning account for over 40% of the energy used (see Figure 1.4). This is why sustainable mechanical systems are so important in green buildings.

HOW IS SUSTAINABILITY MEASURED? You were introduced to the idea of benchmarking and Energy Use Intensity (EUI) in Fundamentals. Averaging over all the buildings in the United States in 2003 (the last year for which there is complete data), the EUI comes out to about 184,000 Btu per square foot per year (580 kWh/m2 per year). This ranged from hospitals, at over 346,000 Btu per square foot (1,091 kWh/m2), to residential buildings, at 87,400 Btu per square foot (276 kWh/m2). In Canada, the mean EUI is 112,500 Btu per square foot per year (355 kWh/ m2 per year). This gives us a way to compare the energy use of different buildings (see Figure 1.5). So what is considered sustainable? Many “green” standards are flexible

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in their criteria for total energy consumption. One of the most energy-efficient standards is Passive House. Thousands of buildings comply with its requirements of total annual building energy use less than 38,100 Btu per square foot (120 kWh/ m2); of that, no more than 4,760 Btu per square foot per year (12%) may be used for HVAC. A small portion of U.S. buildings currently approach this standard, but it is attracting more interest here as viable examples are completed around the country.

WHAT IS EFFICIENCY? Efficiency is the ability of a device to deliver its service for the least possible input of energy. For a heating system the product is the heat delivered to the conditioned space, and for a cooling system it is the heat removed from the interior of the building. The inputs will be gas, oil, electricity, or some other energy source. The performance of mechanical systems can be measured and rated based on the amount of energy they consume and the amount of product they supply or services they deliver. The lower its energy consumption per unit of output, the more efficient the system is. The market and economic shift toward energy conservation and higher-efficiency mechanical systems initially were driven by the 1970 oil embargo. The circumstances created by the embargo led several public and private organizations to develop and implement codes, standards, and guidelines related to energy-efficiency requirements for buildings and homes. The Federal Trade Commission (FTC) determined that new heating equipment must display its energy-efficiency ratings. The Government of Canada's EnerGuide energy-efficiency label is mandatory for room air conditioners, and voluntary for central HVAC equipment. These laws help consumers compare equipment before purchasing. Both the construction of buildings and the efficiency of the equipment

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used in them are prescribed by building codes dedicated to energy, called “energy codes.” One of the most widely used energy standards in the United States is ASHRAE 90.1, first published in 1975. This standard required architects and engineers to design buildings meeting a specified minimum level of energy efficiency. In addition to ASHRAE 90.1, Canada uses the National Energy Code for Buildings (NECB 2011).

the required efficiency of many appliances, from air conditioners to light bulbs. The march toward energy efficiency continues and remains driven by the pursuit of more efficient management of energy flows, delivering maximum human comfort with a minimum of energy use and consumer cost.

Because equipment differs in how it works and what it does, mechanical system performance is rated by In the early 1990s the U.S. EPA several different methods, which introduced the ENERGY STAR we’ll describe later in this manual. label for appliances, computers, The concepts are key, because and HVAC equipment. Natural participating in green construction Resources Canada partnered with and putting together the best HVAC ENERGY STAR in 2001. More recently, systems requires an understanding U.S. Congress acted to increase of the efficiency rating scales as they apply to mechanical equipment.

28%

Transportation

OTHER

32%

Industry

20% ELEVATORS

5% 9%

PLUG LOADS

10% 40%

WATER HEATING

Buildings 16%

LIGHTING

40% HVAC

1.4: Energy used in all U.S. buildings costs $432 billion per year. HVAC units account for 40% of all energy in buildings in the U.S., resulting in over $170 billion per year. This cost can be significantly reduced with energy-efficient technologies.

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EFFICIENCY MUST ACCOUNT FOR OPERATION UNDER VARYING CONDITIONS

Existing High-Performing Building

260 240 220 200 180 160 140 120 100

The Helena

0

World War I Co-op 2010-2011 Benchmark

20

Passive House Std.

40

Empire State Building

80 60

ENERGY RATINGS SAMPLER In most cases, minimum efficiency ratings are specified by mandatory building codes, while stricter, voluntary standards, such as the ASHRAE Standard for the Design of High-Performance, Green Buildings (ASHRAE 189.1) and the International Green Construction Code (IgCC), will call for even greater efficiency. Because different HVAC systems have different ways of operating, the efficiency rating systems also vary from one technology to another. In all, there are many different rating systems, which can rapidly become confusing. To keep confusion to a minimum, we will describe each efficiency rating system when we discuss the equipment to which it applies, later in this manual.

2010 Standard Building Model

280

Energy Use Performance (kBtu/sf)

The simplest way to measure the efficiency of a piece of equipment is to start it up, let it get to a point where it’s warmed up (or cooled off) and is operating in a stable mode, then measure the input power and the output power. However, equipment isn’t actually used that way. In the real world, it turns on and off, operates under widely varying conditions, and may be called on to operate at part load. All these changes can affect efficiency, so the measurements used to report on efficiency must take these variations into account if they are to provide an accurate guide to the cost of future operations. Consequently, a set of efficiency measures have been developed that do take most of these issues into account. However, this means there is a substantial set of different requirements, each appropriate to a particular technology in a particular application.

300

High Rise Row House High Rise High Rise Commercial Residential Residential (Masonry) (Window Wall)

1.5: This graph compares the energy use performance of standard 2010 buildings and current high-performing buildings. All types of buildings have the potential to use much less energy.

1 TEST YOURSELF: 1. Sustainable mechanical systems contribute to the four benefits of green building in what ways? 2. How are green mechanical systems different from standard mechanical systems? 3. What is efficiency? 4. Describe some examples of how the wholebuilding approach can affect HVAC design in high performing buildings.

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Sample Chapter: GPRO Mechanical  

GPRO Mechanical gives experienced mechanical professionals the critical tools to transition from conventional to sustainable construction pr...

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