Evaluation of Building Energy Performance Rating Methods

ASHRAE TRP-1286 Initial Results

Jason Glazer, P.E.

GARD Analytics

January 2006

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Project Overview

• Today’s presentation– Overview of many rating methods– In depth evaluation of five methods

• Work in progress– Gathered data for 29 test buildings– Test five methods with building data– Recommendations

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Overview of Many Methods

• Formal literature search

• Internet search– building benchmark

– building energy benchmark

– building energy rating

– building energy metric

– Building Energy Measure OR Rank OR Gauge OR Grade

– Building Energy Criteria OR Classification OR Merit

– Building Energy Valuation OR Mark OR Yardstick

– Building Energy Target OR Score

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Overview Results

• 88 protocols initially uncovered– 47 commercial (focus)– 31 residential

• Categorization applied– Use of, or reference to, ASHRAE products– Range of approach– Range of applicable building types– Number of users (subjective)

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ASHRAE Referenced• Standard 29-1988 – Methods of Testing Automatic Ice Makers• Standard 52.1-1992 – Gravimetric and Dust-Spot Procedures for

Testing Air-Cleaning Devices Used in General Ventilation for Removing Particulate Matter

• Standard 52.2-1999 – Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size

• Standard 55-1992 – Thermal Environmental Conditions for Human Occupancy

• Standard 62-2001 – Ventilation for Acceptable Indoor Air Quality• Standard 90.1-2001 – Energy Standard for Buildings Except Low-

Rise Residential Buildings• Standard 117-2002 – Method of Testing Closed Refrigerators• Standard 129-1997 – Measuring Air Change Effectiveness• Guideline 1-1996 – The HVAC Commissioning Process (G-1)• Guideline 4-1993 – Preparation of Operating and Maintenance

Documentation for Building Systems (G-4)• ASHRAE Handbook – Fundamentals (HOF)

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Use of ASHRAE DocumentsProtocol Standards Guidelines HOF

29 52.1 52.2 55 62 90.1 117 129 G-1 G-4

LEED x x x x (99) x x

LEED-EB x x x x (99) x x

G/Rated - Portland LEED x x x x (99) x x

LEED™ Supplement for King County

x x x x (99) x x

E-Benchmark x x x x x x

Minnesota Sustainable Design Guide

x x x(89) x (89) x x x

High Performance Building Guidelines

x (95) x(89) x x x

EnergyStar Label for Buildings

x x x(99)

GBTool x x

Numbers in parenthesis are earlier versions of these documents where the number indicates the year.

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Approaches Used

• Points with prerequisites and reference building simulation

• Comparison with building simulations

• Placement within statistical distribution shown graphically or by score

• Direct comparison of multiple buildings to each other

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Range of Buildings

• One specific building type (laboratories)• All building types using national public

database of buildings • Subset of building types using specific

databases or statistical model for each building type

• Common: education, healthcare, hotel, office, retail

• Broad categories or several subcategories

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In-depth Evaluation• Selected by

– Level of adoption– Approach used– Customer focus

• LEED-NC/LEED-EB – USGBC• EnergyStar for Buildings – US EPA• BREEAM – UK BRE• ARCH/CALARCH - LBNL• EnergyPrism Benchmark – Commercial

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Comparisons• Scope of application

• Empirical basis

• Input requirements

• Output and transparency

• Part of certification process

• Effort and expense

• Influences design or retrofit

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Scope of Application – Building Type

• Any building– LEED-NC– Arch/Cal-Arch– EnergyPrism

• Subset of Buildings– LEED-EB– BREEAM– ENERGY STAR Label for Buildings

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Scope of Application - Geography

• U.S. – LEED, ENERGY STAR, EnergyPrism, Arch

• California– Cal-Arch

• Global– BREEAM

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Scope of Application – Building Size

• Some have specific building size range

• Certification costs discourage small buildings

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Empirical Basis - Source

• CBECS – US DOE/EIA– Arch, ENERGY STAR, Energy Prism, LEED-EB

• California proprietary database– Cal-Arch

• Private databases– ENERGY STAR (Hospitals, Hotels)

• No empirical basis– LEED-NC - simulations with 90.1 baseline– BREEAM – ECON 19 comparison

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Input Requirements

• Building area and annual energy usage– Arch and Cal-Arch

• Area by space type, monthly energy usage – ENERGY STAR Label for Buildings

• Building area, annual energy use, end-use– EnergyPrism

• Many inputs for each point sought– BREEAM, LEED

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Output and Transparency – LEED and BREEAM

• Several specific grade levels provide simple recognition by others– BREEAM: Pass, Good, Very Good, Excellent– LEED: Certified, Silver, Gold, Platinum

• Points allow cafeteria style selection of measures

• Lower resolution - not appropriate for multi-building comparisons

• More than energy: environmental

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Output and Transparency – ENERGY STAR

• Number between 0 to 100 with a specific threshold

• Documentation aimed at analyst

• Threshold of 75 provides user understanding if improvement is warranted

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Cal-Arch Output Example

Interpretation needed. No threshold.

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EnergyPrism Output Example

• Like appliance energy label

• No threshold

• Unknown distribution

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Part of Certification Process

• ENERGY STAR, BREEAM, LEED– Recognition to building– Third party gives legitimacy– Widely recognized– Adequate lighting, ventilation, comfort– Utility or government incentives– Leveraged by other organizations

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Effort and Expense

• No cost – an hour to self-assess– ENERGY STAR, EnergyPrism, Arch/Cal-

Arch– 2623 ENERGY STAR certified (Jan 2006)

• With cost – multi-month process– BREEAM, LEED– 359 LEED certified (Nov 2005)

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Influences Design or Retrofit

• Point systems for design– LEED-NC and BREEAM– Directly influence design– Incorporate with the design process

• Consumption based protocols– ENERGY STAR, EnergyPrism, Arch/Cal-Arch– Indirect influence on design– May spur energy oriented retrofits– Do not indicate why building performing poorly– Added risk trying to meet threshold

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Next Steps

• Data from actual buildings– Office, K-12 schools, hospital, lodging

• Test methods – Include test cases for major inputs

• Prepare recommendations for future rating methods

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Questions