Chapter Nine

Impact of Energy and Atmosphere

Abstract

This chapter deals with various aspects of the Energy and Atmosphere Leadership in Energy and Environmental Design (LEED) category including LEED credits and LEED V3 and V4 Rating systems. This is followed by a study of the Building Envelope and exterior wall systems such as curtain walls. Then Intelligent Energy Management Systems such as building automation and intelligent buildings are looked at. A discussion of Mechanical Systems (Air Conditioning, Heating, and Ventilation) includes Types of HVAC Systems and HVAC requirements and deficiencies. This is followed by a study of electrical power and lighting systems including electrical components (e.g., meters, fire alarms, circuit breakers, etc.) and to understand the meaning of electrical terms like horsepower, amps, volts, watts, and harmonics. Solar energy systems (active and passive), their benefits and impact on the environment are outlined. Federal tax credits for energy efficiency are then explained. And finally, fire suppression systems (including types of fire sprinklers, standpipes, fire extinguishers, fire doors, etc.) and continuing advances in fire-detection technology are highlighted.

Keywords

Amps; Building envelope; Enhanced commissioning; Fiber optics; Firestop; Fundamental commissioning; Harmonics; Packaged systems; Solar energy; Tax credits

9.1. General Introduction

Most buildings and facilities today rely on the operation of mechanical and electrical systems to maintain a high level of indoor environmental quality for a building’s occupants. Moreover, according to the U.S. Department of Energy (DOE) building operations consume an estimated 40% of the energy and 74% of the electricity produced annually in the United States. Yet the United States often relies on outdated, inefficient power systems that fail to balance energy supply and demand. It is now becoming critically important to revise our approach toward sustainability and green building and to make our buildings more cost-effective and healthy places to live and work in. As previously discussed, this can now be achieved through the use of green strategies such as the integrated design processes that enable the creation of high-performance buildings wherein all systems and components work together to produce overall functionality and environmental performance while meeting the needs of both owner and tenant. However, property developers, design professionals, and so forth are increasingly turning to green building practices, mainly because green buildings reduce the environmental impact of construction, and improve the health and wellness of occupants. It is no secret that green building clearly represents the future of the American construction industry, and it is already creating a wealth of new opportunities and challenges. Moreover, green construction practices can also open doors to receiving local and state financial incentives. In addition, through integrated design we can now create “Net Zero Energy Buildings” (NZEB): buildings that, on an annual basis, draw from outside sources equal or less energy than produced on site from renewable energy sources. There is also the need to adhere to codes designed to protect the environment, conserve energy, and preserve natural resources. The recently launched International Green Construction Code (IGCC) by the International Code Council (ICC) is an example and addresses many of these issues. The intent of the IGCC is to significantly reduce energy usage and greenhouse gases through mandatory green building design and performance in new and existing commercial buildings. Other primary objectives of the IGCC include preserving natural and material resources both in site development and in land use, in addition to improving indoor air quality (IAQ), supporting the use of energy-efficient appliances, and renewable energy systems, as well as water resource conservation measures.
Thus, because greenhouse gases are directly contributing to air pollution and climate change, there is an urgent need to jump on the green bandwagon. This is becoming even more pressing when we realize that in the United States alone, there are nearly 5 million commercial buildings. Furthermore, commercial buildings and residential buildings together account for roughly 1/3 of all energy consumed, as well as being responsible for 2/3 of the total electricity used within the United States. This is why it is so important for companies to incorporate green construction and green systems. Still, we have yet to see how implementation of the new 2012 IGCC will impact green building systems. Rob Watson, Founding Father of LEED and an International Pioneer in the Modern Green Building Movement, says, “Buildings are literally the worst thing that humans do to the planet. Nothing consumes more energy; nothing consumes more materials; nothing consumes more drinking water, and human beings spend up to 90% of their time indoors so if they are getting sick from their environment, in fact, they are getting sick from their indoor environment not from their outdoor environment.” Watson also believes that it is necessary for us to change our paradigms and way of living.
It is important to understand the many aspects that impact the design and construction of creating green buildings that are both healthy and cost-effective. First, however, it would be prudent to overview of the new LEED V3 and V4 Rating systems, particularly as they apply to the Energy and Atmosphere (EA) category and also a brief discussion of some of the changes and new requirements for acquiring LEED credits in this category. It is important to note that many of the exam questions in the LEED exam tend to focus on the energy credits, especially strategies to optimize energy performance. It would therefore be especially prudent to pay particular attention to this category. For the latest updates relating to the LEED 2009 and LEED V4 certification and test requirements, visit the GBCI and USGBC websites: www.gbci.org; www.usgbc.org.
The LEED V3 requirements have changed significantly from its predecessor, with an increased emphasis on sustainable sites, water efficiency, and EA. In terms of possible credits and points, EA must be considered the most important of the seven categories in the new LEED 2009 Rating System. For certification purposes, EA can now earn up to 35 points out of 100 + 10 (Table 9.1). It should be stressed however that no individual product or system in itself can be LEED certified; they can only help contribute to the completion of LEED credits. The significance of the dramatic changes to the LEED 2009 scoring system cannot be overstated, particularly in how it relates to energy modeling. Energy and Atmosphere Prerequisite 2 (minimum energy performance) and Credit 1 (optimize energy performance) have changed significantly. Thus, the threshold for the prerequisite has changed from 14% to 10% and the points awarded in the optimize energy performance credit have increased from a 1–10 point scale to a possible 1–19 point scale, awarding basically nine extra points for same percentage improvement over the baseline building. But what is perhaps even more interesting is that the baseline itself has changed. LEED project teams are mandated to use the ASHRAE Standard referenced in the applicable Reference Guide and are permitted to use addenda within the most recent Supplement to that Standard. The new LEED V3 is largely governed by the 2007 update of ASHRAE 90.1 (as opposed to the previous version, ASHRAE 90.1 2004). The main modifications relating to LEED requirements include mandatory compliance with Appendix G of ASHRAE 90.1 2007.

Table 9.1

Table showing point allocation for different categories in LEED 2009 rating system

CreditNCCIEBC&SSchools
Sustainable sites2621262824
Water efficiency1011141011
Energy and atmosphere3537353733
Materials/resources1414101313
Indoor environmental quality1517151219
Innovation in design66666
Regionalization44444
Total points110110110110110

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Building construction values in the United States have over the years, become stricter. For example, in climate zone 3A, minimum compliance for roof insulation has increased from R-15 to R-20 and wall insulation has increased from R-13 to R-16.8. Although glass compliance has remained unchanged, different U-values have been introduced based on the type of glass with the former assembly values of U-0.57 and SHGC-0.25 remaining consistent. Thus, using highly efficient glass remains an appropriate method for earning percentage points against the baseline. The significance of this change will be dramatically increased in building types where skin loads represent a large percentage of the peak heating, ventilating, and air conditioning (HVAC) load (i.e., office buildings), but be less significant in spaces where persons and ventilation loads dominate the sizing of the HVAC equipment such as in schools and assembly areas.
In the United States, many state and local governments adopt commercial energy codes to establish minimum energy efficiency standards for the design and construction of buildings, and the majority of these energy codes are based on ASHRAE 90.1 or IECC. It should be noted that several organizations have also produced standards for energy-efficient buildings, but ASHRAE and the U.S. Green Building Council (USGBC) are perhaps the best known. ASHRAE Standard 90.1—2007, Energy Standard for Buildings Except Low-Rise Residential Buildings was established by the USGBC as the commercial building reference standard for the updated rating program, LEED 2009 (Leadership in Energy and Environmental Design) that launched on April 27, 2009. The latest ASHRAE version is the last in a long succession to the original ASHRAE Standard 90-1975 standard, which is becoming increasingly more stringent.
To qualify for LEED certification, HVAC control systems and lighting control system earn very few points on their own, perhaps three points or so. However, with the addition of the necessary sensors and building controls, the number of achievable points grows considerably—to as much as 25 points and even more with the use of fully integrated building systems. This is because with integrated systems, the building can earn multiple LEED points as well as cost savings by taking such measures as having a zone’s occupancy sensor to control both the HVAC and the lighting systems. A comprehensive building operation plan needs to be developed that addresses the many systems heating, cooling, humidity control, lighting, and safety systems. Additionally, there is a need to develop a building automation control plan as well. Energy efficiency measures are recommended to ensure that the building will have the highest percentage of energy savings below the baseline building for the lowest upfront capital costs. Some of these recommended measures may involve minor up front capital costs.
The EA Credit 3 for Commercial Interiors: Measurement and Verification—points can be earned by one of two ways: for projects less than 75% of the total building area, either by having submetering equipment installed to measure and record energy use within the tenant space (2 points) or by negotiating a lease whereby the tenant pays the energy costs and which are not included in the base rent (3 points). OR for projects that constitute 75% or more of the total building area, continuous metering equipment is installed for one of several end uses such as lighting systems and controls or boiler efficiencies (5 points). Some of the other topics that require close attention in preparing for the LEED exam in the EA category are discussed below (For latest LEED addenda updates, visit: http://www.usgbc.org/articles/leed-addenda-update-january-2016).
LEED EA Prerequisite 1: Fundamental Commissioning of Building Systems—Basically, the commissioning plan involves verification that the facility’s energy-related systems are all installed, calibrated, and are performing according to the Owner’s Project Requirements (OPR) and Basis of Design (BOD). The building is to comply with the mandatory and prescriptive requirements of ASHRAE 90.1 2007 in order to establish the minimum level of energy efficiency for the building type. The plans and data produced as a result of the building commissioning will lay the groundwork for later energy efficiency savings. This prerequisite is discussed in detail in Chapter 5. This is an extremely important prerequisite and should be completely understood. Several questions on this subject frequently turn up on the exams.
LEED EA Prerequisite 2: Minimum Energy Performance—The intent of this prerequisite is to establish the minimum level of energy efficiency for the project. It is important to remember here to comply with both the mandatory and prescriptive provisions of ASHRAE 90.1-2007 or State Codes, whichever is more stringent.
LEED EA Prerequisite 3: Fundamental Refrigerant Management—The intent is to reduce ozone depletion. This can be achieved by zero use of chlorofluorocarbon (CFC)-based refrigerants in new heating, ventilating, air conditioning and refrigeration (HVAC&R) systems. For existing construction a comprehensive CFC phase-out conversion prior to project completion is required if reusing existing HVAC equipment (Montreal Protocol—1995).
LEED EA Credit 1: Optimize Energy Performance—The intent is to increase levels of energy performance in comparison to prerequisite standards. Option 1: Whole Building Energy Simulation using an approved energy modeling program (1–19 Points for NC and Schools and 3–21 Points for SC). Option 2: Prescriptive Compliance Path—Comply with ASHRAE’s Advanced Energy Design Guide (1 point) appropriate to the project scope; facility must be 20,000 sq. ft. or less and must be office occupancy or retail occupancy. Option 3: Prescriptive Compliance Path: Advanced Buildings “Core Performance” Guide (1–3 Points). Facility must be less than 100,000 sq. ft.
Exemplary Performance: For project teams pursuing Option 1, new construction must exceed ASHRAE 90.1 2007 Appendix G baseline performance rating by 50% (previously 45.5% for NC) and for existing buildings by 46% (previously 38.5% for NC) to be considered under the Innovation in Design category.
LEED EA Credit 2: On-site Renewable Energy (1–7 points for NC and schools and 1–4 for CS)—The intent is to encourage increase of renewable energy self-supply and reduce impacts associated with fossil fuel energy use. For the minimum renewable energy percentage for each point threshold, see reference guide.
Exemplary Performance: On-site Renewable Energy—For NC and Schools, projects can earn credit for exemplary performance by showing that on-site renewable energy accounts for at least 15% of annual building energy cost. For the CS category, the on-site renewable energy must account for at least 5% of the annual building energy cost to earn an exemplary performance credit.
LEED EA Credit 3: Enhanced Commissioning: This credit (2 Points) is discussed in Chapter 5. The basic intent is to begin commissioning process early in the design process and implement additional activities after systems performance verification.
Exemplary Performance: Enhanced Commissioning: For NC, CS, and Schools, projects that conduct comprehensive envelope commissioning may be considered for an innovative credit. These projects will need to demonstrate the standards and protocol by which the envelope was commissioned.
LEED EA Credit 4: Enhanced Refrigerant Management (2 Points for NC and CS and 1 Point for Schools)—The intent is to reduce ozone depletion while complying with Montreal Protocol. Option 1: Do not use refrigerants. OR Option 2: Select refrigerants and HVAC&R that minimize or eliminate the emission of compounds that contribute to ozone depletion and global warming. Meet or exceed requirements set by the maximum threshold for the combined contributions to ozone depletion and global warming potential (GWP).
LEED EA Credit 5: Measurement and Verification (3 Points for NC and 2 Point for Schools)—The intent is to provide for ongoing measurement and accountability of building energy consumption. Option 1: Develop and implement a measurement and verification (M&V) plan consistent with Option D: Calibrated Simulation as specified in the International Performance Measurement & Verification Protocol (IPMVP) Volume III: Concepts and Options for Determining Energy Savings in New Construction, April 2003. The M&V period must last not less than 1 year of postconstruction occupancy. OR Option 2: Develop and implement an M&V plan consistent with Option B IPMVP Volume III: Concepts and Options for Determining Energy Savings in New Construction, April 2003. The M&V period must last not less than 1 year of postconstruction occupancy.
LEED EA Credit 6: Green Power (2 Points for NC, CS, and Schools)—The intent is to encourage and develop the use of grid source, renewable energy technologies. Option 1: Use the annual electricity consumption results of EA Credit 1: Optimization Energy Performance to determine baseline electricity use. OR Option 2: Determine the baseline electricity consumption by using the DOE Commercial buildings Energy Consumption Survey database. Renewable Energy Certificates (RECs) provide the renewable attributes associated with green power. RECs can be provided at a much more competitive cost than from local utilities. A facility is not required to switch its current utility in order to procure off-site renewable energy for this credit.
Exemplary Performance: Green Power—For NC, CS, and Schools, projects that purchase 100% of their electricity from renewable sources may be considered for an innovation design credit.
Finally, fire protection systems should never be comprised as they serve the purpose of life safety. However, just like other building systems, they should be designed, sourced, installed, and maintained in a manner that is environmental friendly and reduces their impacts on the environment as discussed in Section 9.7 of this chapter.
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