1. Developing Building Energy Use Intensity Benchmarks for Standard 100 Energy Targets
Terry Sharp, PE, CEM
Building Technologies Research & Integration Center
Oak Ridge National Laboratory
Developing Building Energy Use Intensity Benchmarks for Standard 100 Energy Targets
June 27, 2010

2. Presentation Topics
Current needs for existing buildings energy performance benchmarks and targets
Strengths and weaknesses of two development approaches
An integrated synergistic approach
Benchmark results
NOTE: All results shown in this presentation are preliminary.

3. Existing Buildings Energy Performance Baselines and Targets Are Needed For:
ASHRAE Energy Performance Standard
ANSI/ASHRAE/IESNA Standard Revision, Energy Efficiency in Existing Buildings
Need: Benchmark and Targets
Energy Use Reductions in Federal Buildings
Energy Independence & Security Act (EISA 2007)
Need: Benchmark (based on CBECS 2003)
Targets Established (percent below benchmark)

4. Option 1: Benchmark Via Commercial Buildings Energy Consumption Survey (CBECS 2003)
Strengths:
National survey of U.S. buildings
5215 observations
51 building types
6 Office 5 Education
5 Services 5 Assembly
4 Food sales 4 Lodging
3 Restaurant 3 Retail
Balance: health care, public order, malls, warehouse, etc.
5 climate zones
Real buildings, real energy use data

5. Option 1: Benchmark Via Commercial Buildings Energy Consumption Survey (CBECS 2003)
Weaknesses:
Need to split observations for 51 building types across 5 climate zones
Statistical stability decreases proportional to splits
Low observation counts occur for many building types in many climate zones -- decreased reliability
CBECS sampling weights amplify instabilities

6. Baseline Energy Use Intensities (EUIs) Developed From CBECS 2003
Large changes in zonal EUIs
Small observation counts

7. Option 2: Benchmark Via Simulation Results From Dept
Option 2: Benchmark Via Simulation Results From Dept. of Energy Benchmark Buildings
Strengths:
Results readily available
Proto-typical buildings of different types
Modeling performed across ASHRAE’s 15 U.S. climate zones (ASHRAE Standard )
Building models well accepted for R&D purposes
Stable predictions

8. Climate Zones for Benchmark Buildings

9. Energy Use Intensities for Benchmark Buildings by Climate Zone

10. Option 2: Benchmark Via Simulation Results From Dept
Option 2: Benchmark Via Simulation Results From Dept. of Energy Benchmark Buildings
Weaknesses:
One building represents population
One city represents a climate zone
Limited building types
Simulated values = real building values?

11. Option 3: The Integrated Approach
Derive CBECS national median EUIs
Provides real building basis
Retains large sample sizes
Derive ratios of zonal to national average EUIs from building simulations (Department of Energy benchmark buildings)
Use ratios to proportion the CBECS national medians to the 15 ASHRAE climate zones

12. CBECS – National Median Energy Use Intensities by Building Type (kBtu/sqft-yr)

13. Benchmark Buildings: Ratios of Zonal to Average EUIs by Building Type

14. Draft Commercial and Residential Building Energy Performance Benchmarks Based on Integrated Development Approach (kBtu/ft2-yr)
Note: Results shown for 11 commercial building types due to limited space.
Zonal EUI = CBECS/RECS National Median EUI x Zonal Ratio

15. Summary Integrated approach combines strengths of different options
Approach produces regional benchmarks (leading to energy targets)
Provides results for both commercial and residential buildings
Process is straight-forward