Transcript Slide 1

THE WEIDT GROUP
Building Energy Benchmarks
THE WEIDT GROUP
PAGE 1
Sustainable Buildings 2030
© 2008
THE WEIDT GROUP
Presentation 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
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Sustainable Buildings 2030
© 2008
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Introduction

The Benchmark sets the starting point for CO2 Reduction
against which each subsequent target is measure
Sustainable 2030 Benchmarks
100%
90%
Percent CO2 Emissions
80%
70%
60%
50%
40%
30%
20%
10%

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2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
0%
Targets: Reduce CO2 60% by 2010, 90% by 2030
Sustainable Buildings 2030
© 2008
THE WEIDT GROUP
Criteria 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
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Sustainable Buildings 2030
© 2008
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Benchmarking 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
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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
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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
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Comparison of Benchmark System Features
Architecture 2030
Architecture 2030
B3 Benchmarking
Benchmark Goals DOE Benchmarks
EPA National
 See Figure
1
System
Features
on
Page
6
EPA Target Finder
Program
Averages
Easy to use
Accurate
Consistent
Comprehensive
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Yes
Yes
Yes
Yes
Yes, for the
available building
types
Yes, for the
available building
types
No
Yes
Yes
Will vary based on
new CBEC
surveys
Will vary based on
new CBEC
surveys
Yes
16 building types
representing a mix
of public and
private sector
types.
15 building types
representing a mix
of public and
private sector
types.
18 building types
representing a mix
of public and
private sector
types
Over 50
building/space
types covering full
range of public/
private sector
types
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Comparison of Benchmark System Features
Benchmark Goals
Modify Benchmark
based on operational
characteristics
No
Yes
No
Yes
Modify Benchmark
based on special use
conditions of the building
No
Yes
No
Yes
No
Yes, within
available building
types
No
Yes
No
Will contain 5
Minnesota
weather zones
Mixed-use building types
Geographic location
(weather determinants)
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Architecture
B3
DOE
Architecture 2030
2030 EPA
Benchmarking

See Figure
1 System
on Page
6
Benchmarks
EPA Target
Finder Features
National
Program
Averages
16 locations
nationally
Yes
Sustainable Buildings 2030
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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.
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All Comparisons
ASHRAE 2004 DOE Model
ASHRAE 2004 B3 Model
MN 1993 B3 Model
ASHRAE 1989 B3 Model
Target Finder
2010 60% Savings Goal
140
127
125
119
120
117
113
110
100
kBtu / SF
100
93
60%
Saving
s
70 72
80
116
114
119
95
90
60 62
60
47
40
47
51
37
30
20
0
0
0
Warehouse
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Small Hotel
Sustainable Buildings 2030
Medium office
Primary school
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System comparisons All CUT
ASHRAE 2004 DOE Model
ASHRAE 2004 B3 Model
MN 1993 B3 Model
ASHRAE 1989 B3 Model
Target Finder
2010 60% Savings Goal
400
371
350
316
300
278
268
kBtu / SF
250
60%
Saving
s
225
200 198
200
206
178
152
150
100
100
112
148
125
114
107
71
50
0
0
Stand-alone retail
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Hospital
Sustainable Buildings 2030
Supermarket
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Comparisons 1989 B3 to Target Finder
ASHRAE
1989 B3
Model
Target
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%
Building Type Name
Conclusions
The ASHRAE 90.1 1989 B3 Benchmark model results and the Target
Finder results are the best fit of data systems compared in this study.
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Comparison of 1989 B3 to Architecture 2030
National Averages
THE WEIDT GROUP
MN 1993 B3 Model
Arch 2030 National Average
2010 60% Savings Goal
18 0
16 0
160
136
124
14 0
kBtu / SF
12 0
123
122
120
96
10 0
86
78
80
60
78
77
66
50
48
40
31
31
26
31
20
0
College University
Fire Station
Police Station
Nursing
Home/Assisted
Living
Public Assembly
Service
Conclusions
The 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.
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Sensitivity Analysis for Operational Characteristics
Retail Buildings
Heated/ cooled area variations
100
80 hrs/ w k
111
168 hrs/ w k
150
115 hrs/ w k
125
80 hrs/ w k
Target Finder
B3 benchmarking
115 hrs/ w k
DOE
Retail Buildings
operation schedule variations
160
168 hrs/ w k
206
115 hrs/ w k
-
178
50
100
150
100% heated/ cooled
100
reduced cooling/ heating area
91
reduced heating area
96
reduced cooling area
120
100% heated/ cooled
Target Finder
B3 benchmarking
DOE
THE WEIDT GROUP
200
250
125
reduced cooling/ heating area
152
reduced heating area
154
reduced cooling area
176
100% heated/ cooled
178
-
50
100
150
200
KBTU/sf/year
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.
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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.
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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.
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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?
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Sustainable Buildings 2030
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Establish Savings Targets from the
Benchmark
Annual kBtu / SF Benchmark EUI's
Equivalent ASHRAE
1989 B3 Savings % to
meet target finder 60%
goal
ASHRAE
1989 B3
Model
Target
Finder
2010 60%
Savings
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%
Building Type Name
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.
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Analysis of Hospital savings opportunities
Hospital: Gas Boiler/ Water-Cooled Chiller
Total Building Energy kBtu/SF
250.00
208.15
195.4
200.00
179.3
32 %
Savings
154.6
140.5
150.00
100.00
50.00
0.00
Code
1989 Code
1989 Savings
% Savings
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Code
208.15
B1
B1
195.4
12.7
6%
B2
B2
179.3
28.9
14%
B3
B4
B3
154.6
53.5
26%
B4
140.5
67.6
32%
Conclusion:
Hospitals are one example
where current technologies and
design methods are not
available to reduce energy
consumption by 60% today.
Sustainable Buildings 2030
© 2008
THE WEIDT GROUP
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
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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
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Sample Distribution of Code Base Office
Building Consumption
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Office Building Sample
13
12
Different Offcie Buildings
11
10
9
8
7
6
5
4
3
2
1
0
50
100
150
Annual kBtus /SF / year
200
250
Average kBtu/ SF/ YR
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Office Building Percentage Difference from
Average
THE WEIDT GROUP
Office Building Sample
13
12
Different Office Buildings
11
10
9
8
7
6
5
4
3
2
1
-60%
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-40%
-20%
0%
20%
40%
60%
% difference from Benchmark
Sustainable Buildings 2030
80%
100%
120%
© 2008
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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
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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.
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Summary
 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.
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THE WEIDT GROUP
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Sustainable Buildings 2030
© 2008