page 1 sustainable buildings 2030 © 2008 the weidt group building energy benchmarks the weidt group

Sustainable Buildings 2030 © 2008

THE WEIDT GROUP

Building Energy BenchmarksBuilding Energy Benchmarks

THE WEIDT GROUP


THE WEIDT GROUP Presentation AgendaPresentation Agenda

Introduction

Comparison of building energy benchmark methods and systems

Comparison of energy use indexes for different benchmark systems for 13 different building types

Recommended Method for Developing Minnesota Benchmarks

How to Disseminate the Sustainable Buildings 2030 Energy Benchmark System


THE WEIDT GROUP Introduction Introduction

The Benchmark sets the starting point for CO2 Reduction against which each subsequent target is measure

Targets: Reduce CO2 60% by 2010, 90% by 2030

Sustainable 2030 Benchmarks

0%

10%

20%

30%

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60%

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90%

100%

2008

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2013

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2015

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2018

2019

2020

2021

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2030

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THE WEIDT GROUP Criteria for a Good Benchmarking systemCriteria for a Good Benchmarking system

Easy to use and understand

Accurate – for our climate

Consistent – methodology for all benchmarks

Comprehensive – for all buildings we build and can account for the specific program criteria unique to each building


THE WEIDT GROUP Benchmarking Methods in Use TodayBenchmarking Methods in Use Today

Comparing a building to itself – the “tracking” or “baseline” approach

Empirical model from a sample of other similar buildings in a population – Target Finder / Energy Star approach

Results of an energy simulation model with certain pre-defined baseline characteristics, such as meeting an energy code or standard – current Minnesota B3 Benchmarking and DOE method


THE WEIDT GROUP What are Metrics used to Benchmark Buildings?

What are Metrics used to Benchmark Buildings?

For cars we use:Miles per gallon

For lighting efficiency we use:Lumens per Watt

For Cooling equipment efficiency we use:kW/ ton

For buildings we use:Energy Use Intensity (EUI) typically expressed in units of Annual energy consumption per floor area per year kBtu / Square feet / year or maybe …CO2 / Square foot/ year


THE WEIDT GROUP Research Existing Building Energy Benchmarking Systems

Research Existing Building Energy Benchmarking Systems

Target Finder / Portfolio Manager 15 different building types – 5 are different hotel

types

Minnesota B3 Benchmarking system Over 50 different building types based of Current

MN 1993 Energy Code

New DOE Benchmarking system Same types as Target Finder based on ASHRAE

90.1 2004 Energy Code


THE WEIDT GROUP Comparison of Benchmark System FeaturesComparison of Benchmark System Features

See Figure 1 System Features on Page 6Benchmark Goals DOE BenchmarksArchitecture 2030

EPA Target Finder

Architecture 2030 EPA National

Averages

B3 Benchmarking Program

Easy to use Yes Yes Yes Yes

AccurateYes, for the

available building types

Yes, for the available building

typesNo Yes

Consistent YesWill vary based on

new CBEC surveys

Will vary based on new CBEC

surveysYes

Comprehensive

16 building types representing a mix

of public and private sector

types.



types.



types

Over 50 building/space

types covering full range of public/ private sector

types


THE WEIDT GROUP Comparison of Benchmark System FeaturesComparison of Benchmark System Features

See Figure 1 System Features on Page 6Benchmark GoalsDOE

Benchmarks

Architecture 2030 EPA Target

Finder

Architecture 2030 EPA National

Averages

B3 Benchmarking

Program

Modify Benchmark based on operational characteristics

No Yes No Yes

Modify Benchmark based on special use conditions of the building

No Yes No Yes

Mixed-use building typesNo

Yes, within available building

typesNo Yes

Geographic location (weather determinants)

16 locations nationally

Yes NoWill contain 5

Minnesota weather zones


THE WEIDT GROUP Comparison of energy use indexes for different benchmark systems

Comparison of energy use indexes for different benchmark systems

Architecture 2030 EPA Target Finder

Architecture 2030 EPA National averages

B3 Models, 1989, Mn 1993, 2004

DOE 2004

Sensitivity analysis of operational characteristics to compare how Target Finder and the B3 Benchmarking system account for changes in building operation.


THE WEIDT GROUP All ComparisonsAll Comparisons

30

110

70

114

0

113

72

95

60

0

90

116

62

125

100

119

93

119 117

127

37

47 4751

0

20

40

60

80

100

120

140

Warehouse Small Hotel Medium office Primary school

kBtu / SF

ASHRAE 2004 DOE Model ASHRAE 2004 B3 Model MN 1993 B3 Model

ASHRAE 1989 B3 Model Target Finder 2010 60% Savings Goal

60%

Saving

s


THE WEIDT GROUP System comparisons All CUTSystem comparisons All CUT

114

225

112

200

278

125

198

0

152

206

316

178

268

371

71

107

148

100

0

50

100

150

200

250

300

350

400

Stand-alone retail Hospital Supermarket

kBtu / SF

ASHRAE 2004 DOE Model ASHRAE 2004 B3 Model MN 1993 B3 Model

ASHRAE 1989 B3 Model Target Finder 2010 60% Savings Goal

60%

Saving

s


THE WEIDT GROUP Comparisons 1989 B3 to Target FinderComparisons 1989 B3 to Target Finder

ConclusionsThe ASHRAE 90.1 1989 B3 Benchmark model results and the Target Finder results are the best fit of data systems compared in this study.

Building Type Name

ASHRAE 1989 B3

ModelTarget Finder Difference % Change

Warehouse 62 93 na na

Small Hotel 125 119 6 5%

Medium office 100 117 -17 -17%

Primary school 119 127 -8 -7%

Stand-alone retail 152 178 -26 -17%

Hospital 206 268 -62 -30%

Supermarket 316 371 -55 -17%


THE WEIDT GROUP Comparison of 1989 B3 to Architecture 2030 National Averages

Comparison of 1989 B3 to Architecture 2030 National Averages

160

122 123

136

9686

78 78

124

6677

48

31 31

50

2631

120

0

20

40

60

80

100

120

140

160

180

College University Fire Station Police Station Nursing

Home/Assisted

Liv ing

Public Assembly Service

kBtu / SF

MN 1993 B3 Model Arch 2030 National Average 2010 60% Savings Goal

ConclusionsThe national average data is national average data; it occasionally resembles Minnesota data but usually does not. It is not a valid method for setting benchmarks for Minnesota buildings.


THE WEIDT GROUP Sensitivity Analysis for Operational CharacteristicsSensitivity Analysis for Operational Characteristics

Retail Buildingsoperation schedule variations

178

206

160

125

150

111

100

- 50 100 150 200 250

115 hrs/ w k

168 hrs/ w k

80 hrs/ w k

115 hrs/ w k

168 hrs/ w k

80 hrs/ w k

115 hrs/ w k

Target Finder

B3 benchmarking

DOE

KBTU/sf/year

Retail BuildingsHeated/ cooled area variations

178

176

154

152

125

120

96

91

100

- 50 100 150 200

100% heated/ cooled

reduced cooling area

reduced heating area

reduced cooling/ heating area

100% heated/ cooled

reduced cooling area

reduced heating area

reduced cooling/ heating area

100% heated/ cooled

Target Finder

B3 benchmarking

DOE

KBTU/sf/year

Conclusions: Changes in operating hours and the conditioned area of the building, have significant impacts on establishing the buildings benchmark. Variations in the parameters studied show impacts up to 25%. We will need a system that accounts for these variations to develop an accurate Benchmark System.


THE WEIDT GROUP Recommended Method for Developing Minnesota Benchmarks

Recommended Method for Developing Minnesota Benchmarks

The 2004 code is too stringent, would be difficult to achieve 60%.

Target Finder can not be extended to a larger range of building types – we want a consistent methodology used for all building types.

The National Average EUI’s developed by the Architecture 2030 team are not accurate for running a program in this State.


THE WEIDT GROUP Recommendation:

Use the ASHRAE 1989 90.1 Energy Code

Recommendation:

Use the ASHRAE 1989 90.1 Energy Code

A very efficient analysis method for creating a comprehensive list of building types

It will not require expensive data collection of existing building energy use

The code is a rule based system that can be modeled consistently and accurately for all building types.

The ASHRAE 90.1 1989 model data is closest to Target Finder results.

The ASHRAE 90.1 1989 has been the code in place until recently and closely follows the intent of the Architecture 2030 program

Subsequent Code improvements can be easily benchmarked to identify how they alone improve the EUI from the 1989 baseline.


THE WEIDT GROUP Establish Savings Targets from the Benchmark

Establish Savings Targets from the Benchmark

Architecture 2030 proposes the same % reduction for all building types.

For 2010 it establishes a 60% reduction in consumption

Is this feasible for all building types?


THE WEIDT GROUP Establish Savings Targets from the Benchmark

Establish Savings Targets from the Benchmark

The equivalent percentage savings ranges from 62% for the Small Hotel to 40% savings for the Warehouse building type. This analysis raises the question of using a standard savings percentage for all building types or having it vary based on building type.

Building Type Name

ASHRAE 1989 B3

ModelTarget Finder

2010 60% Savings

Goal

Equivalent ASHRAE 1989 B3 Savings % to

meet target finder 60% goal

Warehouse 62 93 37 40%

Small Hotel 125 119 47 62%

Medium office 100 117 47 53%

Primary school 119 127 51 57%

Stand-alone retail 152 178 71 53%

Hospital 206 268 107 48%

Supermarket 316 371 148 53%

Annual kBtu / SF Benchmark EUI's


THE WEIDT GROUP Analysis of Hospital savings opportunitiesAnalysis of Hospital savings opportunities

Hospital: Gas Boiler/ Water-Cooled Chiller

Code B1 B2 B3 B41989 Code 208.15 195.4 179.3 154.6 140.5 1989 Savings 12.7 28.9 53.5 67.6 % Savings 6% 14% 26% 32%

Total Building Energy kBtu/SF

208.15 195.4

179.3

154.6 140.5

0.00

50.00

100.00

150.00

200.00

250.00

Code B1 B2 B3 B4

Conclusion:Hospitals are one example where current technologies and design methods are not available to reduce energy consumption by 60% today.

32 % Savings


THE WEIDT GROUP Development of Building Energy Benchmarks for “Typical” Building Types

Development of Building Energy Benchmarks for “Typical” Building Types

We are completing work on simulating Energy Benchmarks for over 30 different building types.

We have researched average building characteristics from the DOE models and hundreds of projects we have archived.

These models utilize average building characteristics by building type for:

Space use type

Space use distribution

Operational schedules for lights, plugs, etc.

Envelope parameters

HVAC parameters


THE WEIDT GROUP Development of Building Energy Benchmarks for “Typical” Building Types

Development of Building Energy Benchmarks for “Typical” Building Types

What we have found from our review of the data is there is a large variation in consumption results for “Typical” Building types.

The large variation in consumption results is due to the large variation in each projects unique building program requirements, mainly:

Space use type

Space use distribution – this can be significant

Operational schedules for lights, plugs, etc.

HVAC parameters


THE WEIDT GROUP Sample Distribution of Code Base Office Building Consumption

Sample Distribution of Code Base Office Building Consumption

Average kBtu/ SF/ YRAverage kBtu/ SF/ YR


THE WEIDT GROUP Office Building Percentage Difference from Average

Office Building Percentage Difference from Average


THE WEIDT GROUP Dissemination of the Sustainable Buildings 2030 Energy Benchmark System

Dissemination of the Sustainable Buildings 2030 Energy Benchmark System

A web-based calculation tool will be developed to allow project designers to:

Use “default” building characteristic or have the ability to “customize” characteristics based on their unique building program elements.

Editable building characteristics will include:

Building location

Building gross floor area

Building type(s)

Number of floors

Space type, floor area% and hours of use.

Cooling and heating system

Fuel source types for building


THE WEIDT GROUP Dissemination of the Sustainable Buildings 2030 Energy Benchmark System

Dissemination of the Sustainable Buildings 2030 Energy Benchmark System

After results are entered the web-based tool will calculate:

Total Energy Target Standard in kBtu/SF goal based on 2030 savings criteria.

Fuel source end use in kBtu/SF for the Target Standard.

Target Standard CO2 emissions by fuel source.


THE WEIDT GROUP SummarySummary

We can’t use National Averages

We can’t use Target Finder

We need a lot of space type and operational variables

Modeled data can provide us the flexibility and accuracy we need

Modeled data aligns well with the intent of 2030

ASHRAE 89 is the best code base to use to reflect the intent of 2030

We need to formulate the appropriate range of % savings by building type to be cost-effective.


THE WEIDT GROUP

THE WEIDT GROUP

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