Lessons Learned on Causes of High Energy Performance from EPA E NERGY S TAR Buildings ASHRAE 2002 Winter Meeting Seminar 41 Thomas W. Hicks U.S. Environmental Protection Agency Washington, DC

Answer: Common Knowledge QuickTime™ and a Photo CD Decompressor are needed to use this picture Why Get Involved? Is 10 MPG high or low for an automobile? Is 100 kBtu/ft 2 -year high or low for a typical office building? Answer: ?? Missing Comparative Metric

Number of Buildings Large Variation in Energy Performance Worst Performers Best Performers Site Energy Intensity (kBtu/ft 2 -year) National data sets show large variations in energy performance exist even after significant drivers of energy intensity are normalized Basis: Office Buildings, 1995 CBECS

1 to 100 scale was overlayed - creating a national energy performance rating. Energy Performance Rating 1 Worst Performers Best Performers Number of Buildings Rating & Site Energy Intensity (kBtu/ft 2 -year) Basis: Office Buildings, 1995 CBECS

In January 1999, EPA released an energy performance rating system which was intended to be: Objective Reasonably accurate Assess performance relative to peers Originally just for office buildings Recognition is offered (via the E NERGY S TAR Label) for: Buildings whose energy performance is among nation’s top 25% while Meeting current standards for indoor environment as verified by a PE. History

Based on actual annual energy performance Not as-designed performance Source energy not site energy Commonly understood 1 to 100 rating scale Rating of 75 or greater = E NERGY S TAR Accounts for building’s business activity Operating & physical characteristics, climate (HDD & CDD) Adjusts for year to year weather variations El Niños, La Niñas, colder/warmer than normal, etc. Details...Inside the Box

Benchmarking Tool Database (171 buildings) Operating characteristics (i.e. hours, occupants, & PCs) Physical characteristics (i.e. size, location, & climate) Annual energy consumption & expenditures (by fuel type) Exit Interviews 15 minutes, CBECS-like 91 of 171 buildings participated HVAC equipment and systems Energy management equipment and systems Building management Amenities Architectural characteristics Self-Selection Bias Note: 25 of the 171 buildings that earned recognition were removed from the dataset since their size was less than 50,000 ft 2. Data Collection

Compared buildings earning the E NERGY S TAR label in 2000 to buildings found in: CBECS 1995 Top 25%, Average, & Bottom 25% 1,228 office building records 530 records remained after applying screens Sampling weights were applied BOMA Energy Exchange Report ,364 office building records 92 cities in the U.S. Data access limited Note: 1999 CBECS micro data is not publicly available as of presentation date. Approach

Filters applied to 1995 CBECS data set involved: 1) E NERGY S TAR eligibility requirements Weekly hours ≥ 35 Months in use ≥ 11 2) Removal of unreasonable records Electricity consumption > 0 # of workers > 0 3) More physically and operationally comparable data Building area ≥ 50,000 ft 2 Screening Criteria

Basic Comparison * - estimated

Energy & Cost Comparison On average… buildings in the top 25% have annual energy cost nearly $1/ft 2 less to operate Note: Cost in 2000 U.S. Dollars.

Codes and/or original design Application of: energy efficient technologies renewable energy technologies Regular Operations & Maintenance High level to commitment to performance Dedicated on-site energy manager Occupant behavior Some or All of the above Does a Single Path to EE Exist?

Tendencies in Building Characteristics E NERGY S TAR CBECS Top 25%CBECS AverageCBECS Bottom 25% HVAC Boiler62%32%46%49% Chiller69%26%43%65% VAV69%36%50%67% Energy Efficiency EMS85%23%43%56% Economizer71%29%55%73% VSDs57%19%33%45% Motion Sensors47%8%16%21% Management Energy Audit57%23%24%36% Regular O&M99%92%96%98% Equip. Upgrade76%-- Percentage of Buildings in Data Set

Amenities Percentage of Buildings Notes: Data on Class A, Elevators, Escalators, Atriums, and Balconies was not available for CBECS and BOMA EER data sets. CBECS data on glass as the predominant exterior wall material is as follows: Top 25% (12%), Average (15%), Bottom 25% (20%). Data was not available from BOMA EER data set.

Who’s Running the Building? Title of Person with Daily Responsibility Noteworthy: rarely have on-site energy managers, building engineers and custodians account for nearly 75%

Glass Characteristics Window Types Percentage of Glass on Exterior Wall # of Panes for Each Window Noteworthy: Low-e glass rare, no triple pane windows, single pane as likely as double pane, and no bias toward % of glass.

What did They Upgrade? 76% had completed an energy upgrade within the last 3 years, here’s what they did... Energy Upgrade Areas Noteworthy: majority of upgrades involves Lighting, HVAC, or controls, only 4% upgraded with renewables, and just 1% attempted to modify occupant behavior. Renewables included installations of PV electric generation, solar DHW, and geothermal.

Operations & Maintenance What building systems are being actively covered in the building’s O&M plan? O&M Areas

Why is Building Efficient? In the opinion of the building manager or representative, why did the building qualify? (only 3 choices) Reason Building is Energy Efficient Noteworthy: Original design is the least cited reason for building being energy efficient.

Systems Covered by EMCS? 85% have an EMCS, here’s what systems they are controlling... Building Systems Controlled by EMCS Noteworthy: nothing, no surprises here.

Conclusions Sample size is relatively small and is subject to self- selection bias, but there appears to be... No single path to achieving energy-efficiency High level commitment to energy-efficiency Coupled with the Application of good practice technologies And Good operating practices Little support that any of the following has an impact: Renewables Percentage of exterior glass Original design