HCB 3-Chap 24B: Design for EE1 Chapter 24 B: DESIGN FOR ENERGY EFFICIENCY Agami Reddy (July 2016) 7. Building energy simulation programs - Advantages - Uncertainty in simulations - Simulated vs measured performance 8. Energy use in U.S. and ongoing efforts by government 9. Energy benchmarking and rating 10. Building codes and standards - DOE building prototypes - Basis of standard development 11. Energy efficiency guides 12. Green buildings 13. Net-zero buildings

2 Simulation Programs Building thermal simulation: -allows one to model a building before it is built or before renovations are started -allows various energy alternatives to be investigated and options compared to one another -can lead to an energy-optimized building or inform the design process -much less expensive and less time consuming than experimentation (every building is different) HCB 3-Chap 24B: Design for EE

3 Simulation Programs Energy 10 HEED and Climate Consultant (free of charge- UCLA)- DOE-2 EQuest (can be downloaded free of charge)- very widely used worldwide! EnergyPlus (can be downloaded free of charge)- research tool TRNSYS (Univ of Wisconsin)- research tool TRACE- Trane Company HAP- Carrier Company HCB 3-Chap 24B: Design for EE

4 EnergyPlus Software Copyright U.S.D.O.E. - All rights reserved. Fully integrated building & HVAC simulation program Based on best features of BLAST and DOE-2 plus new capabilities Windows 95/98/NT/2000/XP & Linux Simulation engine only Interfaces available from private software developers Widely used for both research and higher end designs Arguably a state of the art program- best in the U.S.

HCB 3-Chap 24B: Design for EE5 Uncertainty in Building Energy Simulations Specification uncertainty: due to differences between the way the building (physical construction as well as its materials and systems) is simulated and the way it is actually built; Modeling uncertainty: due to the simplifying assumptions in the models of the various energy flows in the building. Numerical uncertainty arises because of the manner of coding and solving the various equations (discretization, numerical convergence,…). Scenario uncertainty which is due to improper specification of the forcing functions. For example, the outdoor air conditions used for the building simulation may be from a location several miles away from the building. Further, there is stochasticity in the diurnal scheduling of the building over the year (after all, buildings are occupied by people), which current-day simulations fail to capture satisfactorily.

HCB 3-Chap 24B: Design for EE6 FIGURE Comparison of modeled and measured energy use in several buildings which applied for LEED certification (Courtesy of Turner and Frankel, 2008). EUI is the energy use index in units of kBtu/sq.ft.

HCB 3-Chap 24B: Design for EE7 FIGURE Comparison of predicted and observed energy consumption for 82 new single-family houses in France. C the = predicted and C obs = observed consumption. The dashed line corresponds to perfect agreement (note suppressed zero and different scales). 1 kWh = 3.6 MJ = kBtu. (Courtesy of Marchio, D. and A. Rabl., 1991.)

8 U.S. Building Energy Scene  Building energy cost about $400 billion in 2010 dollars  Buildings consume 40% of total primary energy which is greater than transportation (28%) and industry (32%)  Residential buildings consume 21 quads of energy (54 % of building energy and 22.3 % of US total) –and commercial buildings about 17.9 quads  Also about 74% of electricity produced in U.S.  Responsible for 49% SOx and 40% of CO2  Fresh water use- 17%  Generate 30% of waste HCB 3-Chap 24B: Design for EE  Number of residences: 115 M  Number of commer/indust:5M with 1.6 million built each year and 2% of commercial buildings undergo major repairs

9 HCB 3-Chap 24B: Design for EE Figure 1.1 Primary energy consumption statistics as percentages: worldwide, different end-use sectors in the U.S., and sources of primary energy to the building sector (BEDB, 2011).

10 U.S. Department of Energy - Energy Efficiency and Renewable Energy Program The mission of the Building Technologies Office (BTO) is to develop technologies, techniques, and tools for making buildings more energy efficient, productive, and affordable. -BTO focuses on improving commercial and residential building components, energy modeling tools, building energy codes, and appliance standards. -This Web site provides information and resources for industry professionals to help reduce the energy use of new and existing buildings and strengthen the nation's energy future. Key Activities -Research and Development -Market stimulation -Building codes and equipment standards HCB 3-Chap 24B: Design for EE

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What is benchmarking? Benchmarking mainly consists in comparing the measured consumption with reference consumption of other similar buildings, or generated by simulation tools, to identify excessive or unacceptable costs. Cycle of Improvement (Department of Energy, 2013) 12 An important issue in benchmarking is the use of performance indexes to characterize the building. Commonly used index: Energy Use Intensity HCB 3-Chap 24B: Design for EE

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14 EPA Portfolio Manager Energy efficiency ratio of Source = Actual EUI / Predicted EUI e.g. Ratio=201.5/282.9= which implies a rating = 72. Joint effort between the US EPA and US DOE. Tool enables users to: - Track multiple energy and water meters -Verify building energy performance -Determine energy performance ratings HCB 3-Chap 24B: Design for EE

EPA Portfolio Manager HCB 3-Chap 24B: Design for EE15 Regression based corrections to EUI for offices: - Natural log of gross square foot - # of personal computers (PCs) per 1,000 sq.ft - Natural log of weekly operating hours - # log of workers per 1,000 sq.ft - HDD x % of the building that is heated - CDD x % of the building that is cooled

HCB 3-Chap 24B: Design for EE 16 Two different rating systems: (a)Building Energy Quotient (EQ) ratio of measured EUI to the median EUIof buildings in the same category [ 0 (best), 100 (median)] (b) Building Asset Rating is similar but energy use is determined by modeling and simulation- this it is reflective of the design- relevant for real estate transactions EUI- energy use index (Btu/ft^2/yr) ASHRAE bEQ

Energy IQ : Developed by LBNL, is a benchmarking tool for non-residential buildings. It provides an assessment of the existing energy use and a list of opportunities and recommendations for cost effective investments. ORNL: The benchmarking spreadsheets developed by ORNL allow one to identify where one’s specific office building ranks relative to others. They calculate the energy use intensity of the building, provide the typical (median) EUI for office buildings with the same characteristics as yours, and identify where the building's performance ranks compared to others. 17 OTHER RATING TOOLS HCB 3-Chap 24B: Design for EE

Commercial Buildings Energy Consumption Survey (CBECS) database: The 2003 CBECS database- building characteristics, system descriptions, energy expenditure, and energy consumption for 6,380 commercial buildings across the US. This data represents all the fifty states and the District of Columbia. There are about 1400 office buildings in this database. All the buildings have over 1000 square feet of floor area. The National Oceanic and Atmospheric Administration (NOAA) has defined the climate zones as groups of climate divisions, which are regions within a state that are as climatically consistent as possible. The first survey was conducted in The most recent survey-early April CBECS is currently updated on a quadrennial basis (US EIA 2012). 18HCB 3-Chap 24B: Design for EE

Building Energy Codes: IECC equiv. adoption as of Feb 2014 HCB 3-Chap 24B: Design for EE19

20 Building Codes and Standards Generally established at state level or municipalities based on codes developed nationally. These in turn are based on standards developed by professional societies, such as ASHRAE 90.1 (DOE will require that states adopt it under Energy Policy Act of 1992) State energy codes: -residential: Model Energy Code (MEC)- REScheck -commercial: Commercial Energy Code-COMcheck Federal govt. has their own codes for residences and commercial buildings HCB 3-Chap 24B: Design for EE

21 Standard provides minimum guidelines for energy conservation design and operation. -Prescriptive path: -materials and methods for design and construction of buildings are specified -System performance path: requirements for each component, system or sub-system of building are set - Energy cost budget method: performance of the building as a whole is set as a design goal (Btu/ft^2/yr). Any combination of material, systems and operating procedures can be used. Allows greater flexibility for innovation This is a code-intended standard. As such, it is written in unambiguous language intended to allow a code official to say “that complies” or “that doesn’t”

HCB 3-Chap 24B: Design for EE22 FIGURE Different compliance paths for ASHRAE standard 90.1

DOE’s Commercial Reference Building Models formerly DOE’s benchmark buildings (Bing Liu, PNL 2010) ruction.html ruction.html Principal Building Activity Building PrototypeFloor area (ft²) Number of Floors HeatingCooling Primary System Secondary System Office Small office5,5001Heat PumpUnitary DXCAVNo Medium office53,6003Gas furnaceUnitary DX VAV w/ elect. reheat No Large office498,60012Boiler Chiller, cooling tower VAV w/reheatNo Mercantile Standalone retail24,6951Gas furnaceUnitary DXCAVNo Strip mall22,5001Gas furnaceUnitary DXCAVNo Education Primary school74,0001Gas furnaceUnitary DXCAVNo Secondary school210,9002Boiler Air cooled chiller VAV w/reheatCAV Health Care Outpatient health care 40,9503BoilerUnitary DXVAV w/reheatNo Hospital241,4105Boiler Chiller, cooling tower VAV w/reheatCentral CAV 23 HCB 3-Chap 24B: Design for EE And more……

Small Office Medium Office Floor area (ft²) Number of Floors Aspect Ratio WWR 53, % Large Office Floor area (ft²) Number of Floors Aspect Ratio WWR 498, (plus basement) 1.540% Office Prototypes Floor area (ft²) Number of Floors Aspect Ratio WWR 5, % 24 HCB 3-Chap 24B: Design for EE

Stand-alone Retail Floor area (ft²) Number of Floors Aspect Ratio WWR 24, % Strip Mall Floor area (ft²) Number of Floors Aspect Ratio WWR 22, % 2 Mercantile Prototypes2 Education Prototypes Primary School Floor area (ft²) Number of Floors Aspect Ratio WWR 74,0001NA35% Floor area (ft²) Number of Floors Aspect Ratio WWR 210,9002NA33% Secondary School 25 HCB 3-Chap 24B: Design for EE

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Alternative June 2010 PI (exclude receptacle loads in the saving calculations) 27 HCB 3-Chap 24B: Design for EE

28 FIGURE Energy efficiency improvements in ASHRAE Standard 90.1 for commercial buildings in successive versions from 1975 till 2013 (Courtesy of Bing Liu, Pacific Northwest National Laboratory, 2015)

Report uploaded onto internet - documents the process of how efficiency standards of different building types are developed by DOE and its national laboratories. - Provides good description of the methodology adopted by the ASHRAE to develop its Advanced Energy Design Guides (AEDGs). HCB 3-Chap 24B: Design for EE 29 Technical Support Document: Development of the Advanced Energy Design Guide for Medium to Big Box Retail Buildings – 50% Energy Savings Eric Bonnema, Matt Leach, and Shanti Pless National Renewable Energy Laboratory

Advancing Energy Guidance Move industry toward net- zero-energy buildings –Small office buildings –Small retail buildings –K-12 –Warehouses (free download) HCB 3-Chap 24B: Design for EE 30

What are the purposes of making a building “green”? Resource efficient –Conservation of Resources –Material Use –Energy –Water Use Environmental Impact Reduction –Air Pollution –Water Pollution –Indoor Air Quality –Soil/Land Pollution/Land Use –Light Pollution –Species Protection Socially Acceptable Delivery HCB 3-Chap 24B: Design for EE31

U.S. Green Building Council Founded in 1993, USGBC is a coalition of leaders from across the building industry working to promote buildings that are environmental responsible, profitable and healthy places to live and work. USGBC’s purpose is to: - Integrate building industry sectors - Lead market transformation - Educate owners and practitioner s HCB 3-Chap 24B: Design for EE 32 National nonprofit organization based in Washington, D.C. Diverse membership or organizations Consensus-driven Committee-based product development Developer and administrator of the LEED Green Building Rating System

HCB 3-Chap 24B: Design for EE 33 LEED Green Building Rating System 1)Voluntary, consensus-based national standard for developing high-performance, sustainable buildings. 2)Members of the U.S. Green Building Council representing all segments of the building industry developed LEED and continue to contribute to its evolution 3)Several LEED certification standards:  New construction and major renovation projects (NC)  Existing building operations (EB)  Commercial interiors projects (CI)  Core and shell projects (CS)  Homes (H)  Neighborhood development (ND)

LEED-H Homes: “Whole Building Life Cycle” Points Location and Linkages 10 Sustainable Sites 14 Water Efficiency12 Indoor Air Quality14 1 ENERGY STAR with Indoor Air Quality Package (IAP)10 2 Combustion Venting Req 3 Humidity Control 1 4 Outdoor Air Ventilation Req+3 5 Local Exhaust Req+2 6 Supply Air Distribution Req+2 7 Supply Air Filtering Req+3 8 Contaminant Control Req+2 9 Radon Protection Req+1 10 Vehicle Emissions Protection Req Materials and Resources24 1 Home Size: Smaller than National Average 10 2 Material Efficient Framing Req+2 3 Local Sources Materials 3 4 Durability Plan Req+3 5 Environmentally Preferable Products Req+4 6 Waste Management Req+2 Energy and Atmosphere 29 Homeowner Awareness 1 Innovation and Design Process 4 Project Maximum Points: 108 Certified pts; Silver pts; Gold pts; Platinum pts HCB 3-Chap 24B: Design for EE34

HCB 3-Chap 24B: Design for EE 35 LEED: Target and Credit System  Five credit categories

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HCB 3-Chap 24B: Design for EE 37 ASHRAE 189 Standard 189 is a minimum Green Building Standard and not a rating system (can be used by both LEED and Green Globes). - The International Code Council plans to codify it. - Will use existing Building Inspectors for Certification. -Uses CO 2 as one of its performance metrics -Dual prescriptive/performance paths reduces the need for extensive calculations. - Sets a high level of performance – 30% better then ASHRAE (~50% better then ). - Present level of environmental performance equals LEED high silver (under LEED NC 2.2.)

Green Building Efficiency + On-site Generation = Zero Net Energy (ZNE) Building One can reduce energy use in homes by 20% with simple retrofits and upto 50% by elaborate retrofits From Randolph and Masters HCB 3-Chap 24B: Design for EE38

AIA Architecture 2030 Challenge Calls for incrementally reducing energy use from 50% reduction over existing buildings so as to reach carbon neutral new buildings by HCB 3-Chap 24B: Design for EE

40 Though building design involves more than just energy considerations, the “gas gauge or slide-bar” concept suggested by Ed Mazria is useful for practitioners to relate to:

HCB 3-Chap 24B: Design for EE 41 ASHRAE proposes to implement the sustainability-oriented objectives by focusing on five targeted areas: -Energy and resources -Indoor environmental quality -Tools and application -Equipment, components and materials -Education and outreach Design guides Design software Technology tools Products

42 USDOE- Net-Zero Initiatives Energy Independence and Security Act of 2007: Congress passed the Net-Zero Energy Commercial Building Initiative to support the goal of net-zero energy for all new commercial buildings by 2030, and specifies a net-zero target for 50% of the U.S. commercial buildings by 2040 and net zero for all U.S. commercial buildings by DOE has launched three initiatives: - Retailer Energy Alliance (17% ft 2 ) - Commercial Real Estate Energy Alliance(21%) - Hospital Energy Alliance (17%) HCB 3-Chap 24B: Design for EE

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HCB 3-Chap 24B: Design for EE44  Understanding of benefits provided by building energy simulation programs  Knowledge of uncertainties in building energy simulations and reasons for difference between measured and simulated energy data  Understanding of the importance of building energy and different U.S. initiatives and labs working in this area  Knowledge of energy benchmarking and rating methods  Understanding the importance and structure of building energy codes and standards  Understanding how detailed simulations of certain building prototypes support building energy code development  Understanding of ongoing work on green buildings by several organizations Outcomes