Overview of Commercial Existing Building Commissioning and M&V Approaches

July 7, 2009 Regional Technical Forum

Dave Moser, P.E.

Agenda Topics:

• Existing building commissioning (EBCx) ◦ Brief overview • Utility EBCx programs ◦ Preliminary results from PECI’s California EBCx programs ◦ Results from recent process and impact evaluations • M&V Approaches ◦ In-program M&V and ex post impact evaluation ◦ Formal and informal approaches • Persistence ◦ Strategies for ensuring persistence of savings ◦ EBCx measure life

What is EBCx?

A

systematic process

for investigating, analyzing, and optimizing the performance of building systems through the identification and implementation of Facility Improvement Measures and ensuring their continued performance.

The goal of EBCx is to

make building systems perform interactively

to meet the Current Facility Requirements and provide the tools to support the continuous improvement of system performance over time.

What happened to ‘RCx’?

It’s still here.

EBCx is a

comprehensive term

that encompasses the more narrowly focused process variations of: • Retrocommissioning (

RCx

) ◦ Buildings that have never been Cx’d / RCx’d • Recommissioning (

ReCx

) ◦ Buildings that have been Cx’d / RCx’d in the past • Ongoing commissioning (

OCx

) ◦ Systems in place for continual improvement

Why EBCx?

Owners don’t typically receive fully functional building systems at initial occupancy Buildings are more complex; systems are becoming increasingly specialized and integrated Current facility use may be dramatically different than original design Source: LBNL, Dec 2004 http://cx.lbl.gov/cost-benefit.html

LBNL Study Summary: EBCx

Cost per Sq. Ft.

$0.27

Energy Savings 5-10% of whole bldg, up to 25% Simple payback (years) 0.7

Non-energy Benefits (per sq.ft.) $0.18

The 2004 study is currently being updated by LBNL. Should be finished by the end of 2009. Also covers new building commissioning.

Non-Energy Benefits with EBCx

Median value = $0.18 / sf Range = $0.10 - $0.45 / sf Significant when compared with the energy savings potential of $0.15 - $0.30 / sf

EBCx Process

Looks at building as a system Deep analysis during investigation For more info: EPA’s “A Retrocommissioning Guide for Building Owners”.

http://www.peci.org/Library/EPAguide.pdf

EBCx Findings: Big Energy Wasters

Equipment running more than needed Cooling or heating air or water more than needed Heating and cooling at the same time Moving too much air or water Mostly controls related.

EBCx Results from the Field

Note: PECI’s results (not ex post evaluation)

EBCx Results from the Field

Highlights: Median annual EBCx project savings of 5% electric energy, 6% gas • Slightly lower than expected, perhaps due to: ◦ Relatively low investigation incentive of $0.10 / sf • Savings are based on provider calcs, not ex post evaluation ◦ Impact evaluations are currently underway Top five measures make up 60% of the total kWh savings • Airside economizers • Scheduling • Pump VFDs • Fan speed variation ◦ Lower duct static setpoint, reset duct static setpoint, etc.

PECI’s CA EBCx programs since 2006

SCE SDG&E SMUD PG&E Big goals for RCx.

For large commercial buildings (>100k sf). Currently researching ways to make EBCx cost-effective for smaller buildings.

EBCx Program Results

PECI’s 2006-’08 EBCx programs So far, only a process evaluation of the SCE program has been published Other impact evaluations for 2004-05 California EBCx programs are available at calmac.org, including: LA County program (retrofit and EBCx, implementer: LA County) MBCx program (implementer: SCE) BTU program (implementer: QuEST) SDG&E program (implementer: PECI)

EBCx Program Results

Impact and process evaluation for PECI’s “2004-2005 San Diego Gas and Electric Retrocommissioning program” Four buildings in program. Success of program led to CA EBCx programs with more aggressive goals. Summary of ex post savings: • 2.0 kWh / sf savings • 11.9 kBtu / sf savings • 9.4% kBtu whole building energy savings

M&V Approaches to EBCx

A summary of the current state of M&V in EBCx: The California Commissioning Collaborative’s “Verification of Savings Project: Existing Methods Report.” http://resources.cacx.org/library/HoldingDetail.aspx?id=473 Or http://tinyurl.com/kw5q2p Prepared by QuEST and PG&E

Highlights from the report

Traditionally, EBCx focuses on system performance, M&V focuses on energy savings measurement Can be differing goals Most utility EBCx programs use ‘informal’ in-program savings verification methods ‘Informal’ = approved savings calcs and measure implementation verification. Formal M&V, which may be compliant with IPMVP or ASHRAE, occurs during ex post impact evaluation.

‘In-program’ = during implementation of the program, as opposed to during the ex post evaluation (after the program is finished).

Some have attempted to used in-program formal methods MBCx: IPMVP option B (retrofit isolation) or C (whole building) • Not completely adherent, though

Informal method: investigation phase

EBCx provider / agent identifies measures and calculates savings during the investigation phase Typically ‘custom’ spreadsheet-based savings calcs Based on short term trend data, spot measurements, functional tests May or may not include direct measurement of energy / power Program implementer reviews and approves calcs and supporting documentation (trend data, etc)

Informal method: implementation phase

After implementation, provider collects implementation verification data and submits to utility Data types include short term trends, photos, screenshots, functional test forms May or may not include direct measurement of energy / power 100% 80% 60% 40%

Building B Upper Floor Space Pressurization System

As-found condition: high return fan speeds, erratic and inaccurate space pressures Fan speeds drop and space pressure stabilizes after offset is added 20% Program implementer reviews and approves data 0.50

0.40

0.30

0.20

0.10

0% Sun 3/29/09 Sun 4/5/09 Sun 4/12/09 Sun 4/19/09 Sun 4/26/09 Fan Speed

Date

Static Pressure Sun 5/3/09 Sun 5/10/09 Sun 5/17/09 0.00

Sun 5/24/09 Static Pressure Setpoint

Formal M&V during EBCx projects?

It’s possible, but hasn’t been done on a wide scale yet In-program formal M&V would: • Require add’l resources and time • May take focus away from other program activities • May be impractical in some cases

From IPMVP April 2007.

Ex post evaluations

Should be based on formal approaches But aren’t always. For California program evaluations, they strive for adherence to IPMVP, but sometimes fall back to just site visits and reviewing calc methodologies.

In CA, the firewall between implementers and evaluators may be a barrier to implementing in-program formal M&V.

• Little chance of implementers and evaluators working together.

• Opportunity for in-program M&V in the NW? Or at least better communication between implementers and evaluators?

Continued research on EBCx M&V

CCC’s “Verification of Savings” project Create evalulation framework for verification of EBCx project savings Develop guidelines for new and existing methods • “

Guidelines for Verifying Existing Building Commissioning Project Savings - Using Interval Data Energy Models: IPMVP Options B and C

” ◦ Already published. May be viable options for EBCx.

◦ Jeremy Litow presented on this at a recent RTF meeting, for grocery stores ◦ Guidelines will be used on pilot EBCx projects in upcoming PIER research ◦ http://resources.cacx.org/library/HoldingDetail.aspx?id=477, or http://tinyurl.com/n7tz4t

Continued research on EBCx M&V

CCC’s “Verification of Savings” project continues • Additional guidelines based on both formal and informal methods are currently under development as part of this project ◦ IPMVP option A (retrofit: key parameter) ◦ IPMVP option B (retrofit: all parameter) ◦ IPMVP option D (calibrated simulation) » (maybe) ◦ Performance verification with trend data and inspection

Investigation-phase savings calcs

SCE process evaluation said, ‘Simplify!’ PECI is currently working with SCE and other stakeholders to develop deemed savings estimates for common EBCx measures • Current task: compare deemed savings estimates with custom calculations, for EBCx projects from ’06-’08 SCE program

Investigation-phase savings calcs

Some standardized calculation tools are available • Some designed for use by an ‘expert’ user • Future tools will be developed for use by less experienced users Simplifying calcs would allow providers to spend more of their time in buildings looking for EBCx opportunities • Calcs / deemed estimates need to be sufficiently accurate, though

Making Energy Benefits Last

Persistence is an issue with EBCx measures Operational measures can more easily be undone than retrofit measures Various methods for ensuring persistence: Owner / operator training (key!) Updated building documentation / systems manuals Performance tracking • Building benchmarking • Utility bill / energy use tracking (whole building level) • Trending of key metrics (systems level) ◦ Especially for measures that are least likely to persist

Performance Monitoring Some utility EBCx programs include a performance monitoring component

Whole building • BC Hydro (NorthWrite tool) • MBCx • Can also be used for estimating savings Systems-level • San Diego Gas & Electric EBCx Program ◦ Use either the BAS or an overlay such as ENFORMA or PACRAT

How long do EBCx measures live?

Many estimates, little hard research Utility program impact evaluations: • 2004-05 SDG&E impact evaluation says, “use a savings declination curve that

drops below 100% starting in year one

, but that is

above 0% beyond eight years

.” • Bing Tso et al. estimated that for the assumed measure lives and the mix of measures in the Oakland Energy Partners and BTU programs, savings persistence is about

30% at year 10

.

Other research: • PIER “Investigate Commissioning Persistence” found savings from EBCx

decreases by 9% per year

• PG&E assigns a measure life of 3, 5, 8 or 12 years to each EBCx measure type

EBCx measure life Upcoming LBNL study on Cx / EBCx (2009) will address measure life

At least will assemble current research / thinking on the topic

Summary

EBCx is a proven way to optimize a building’s performance Both energy and non-energy benefits are realized Most in-program M&V for EBCx programs has been light on the M, heavy on the V Have relied on the ex post impact evalulations for the M&V Measure persistence should always be addressed Persistence strategies need to be accepted, understood, and useable by operating staff for success

Questions / Discussion

Thank you!

Dave Moser, P.E.

Senior Engineer [email protected]

503-595-4459