Standard Protocol Development for Advanced RTU Control Retrofit August 15, 2013 Presentation to: Regional Technical Forum RTUG Subcommittee Sponsored by: Bonneville Power Administration Presented by:Michael Baker, SBW Consulting, Inc. Bill Koran, NorthWrite, Inc.

Agenda Introductions Review Specification for Advanced RTU Control Retrofit Measure Developing an RTF Standard Protocol Subcommittee Guidance on How to Proceed 2 August 15, 20013

Key Terms Premise – a collection of utility meters that generally serve an entire building but can be a portion of a building as in the common areas of a mall. Premise interval metering – measurement of power at the utility meters for intervals of time. Used to derive daily premise energy use. Unit Power – in this context is the power draw of a retrofit RTU. Signal to Noise – the change in use due to the measure is the signal. Other unrelated use on the premise or unit meter is the noise. Cycling – refers to switching between standard and efficient mode for the advanced controls. Standard more tries to emulate baseline conditions, but has its limitations. Daily cycling has been used at PNNL sites. Other trends – refers to changes in premise energy use unrelated to the measure, such as modification to set points 3 August 15, 20013

RTF Standard Protocols – Development and Application Develop  Measure specification  Define best practice savings estimate  Identify candidate simplified methods  Data to prove simplest reliable method is … Not available or sufficient - approve a Provisional protocol and use in collecting needed data Available – approve protocol as Proven Apply  Two options Use in estimating savings for all projects Use in estimating savings for a sample in support of impact evaluation  Can be applied by a program operator, subject to “faithful application” review by an impact evaluator 4 August 15, 20013

Protocol Measure Specification Eligible systems  Rooftop package and split systems providing heating, cooling and ventilation with constant or multi speed supply fans and constant or multi speed compressors. Either gas or electric (resistance or heat pump) heating. RTF Baseline  Pre-conditions Eligible controls retrofit  Supply fan control using variable speed drive, multi-speed or cycling; demand-controlled ventilation; and differential, integrated economizer control; control of heating and cooling coordination with fan speed optimization.  Can operate in standard (baseline simulation) and efficient modes and cycle between modes on a daily basis 5 August 15, 20013

Test sites and their characteristics Everett Service Center  Heat pump  Office and warehouse  6 of 6 RTU retrofit Staples  Gas pack  Retail  5 of 6 RTU retrofit Federal Way Commons  Heat pump  Mall common Area  11 out of 11 RTU retrofit 6 August 15, 20013

Best practice savings estimates Definition  Long-term cycling – approximately 1 year  Interval measurements of true power for each unit used to derive total daily kWh for all retrofit RTUs  Savings derived from comparison ECAM change point models of daily temperature vs. total unit kWh  Models for standard and for efficient mode days Limitation  Cannot model other improvements such as RCx  Standard mode may not equal baseline Broken economizer Fans set to Auto 7 August 15, 20013

Can we simplify best practice method? Simplification  Use utility interval meters to derive total daily premise-level electric use  Avoids costly unit-level power measurements Challenge  Signal to noise ratio  How much of the premise-level use is associated with the RTUs Test  Model same period of cycling  Compare savings and uncertainty 8 August 15, 20013

Premise vs. Unit Cycling models Same time periods for each model at a site 9 August 15, 20013

Everett Service Center Models 10 August 15, 20013

Everett Service Center Interval Models 11 August 15, 20013

Staples Models 12 August 15, 20013

Banner Bank Models 13 August 15, 20013

Federal Way Commons Models 14 August 15, 20013

Simplified method #1 – Premise level pre/post Method  Derive daily premise kWh from utility interval metering  ECAM change point models comparing pre and post years Advantages  Avoids need to cycle  Captures true baseline  Captures other efficiency improvements made at the same time Limitations  Requires interval metering (what is the status of AMR?)  Reliability depends on signal to noise  Cannot handle unrelated trends  Protocol would have rules about acceptable model residuals 15 August 15, 20013

Comparison of unit-cycling to premise pre/post models Different time periods for each model at a site. Placed on common time using TMY3. 16 August 15, What happened?

What Happened #1 Everett Service Center Changes over Time 17 August 15, 20013

What Happened #1 Everett Service Center Changes over Time RTU Power Model 18 August 15, 20013

What happened #2 Staples Ventilation Changes Pre-install interval meter baseline Post-install baseline emulation 19 August 15, 20013

More Challenges: Federal Way Commons Baseline RTU Power Scatter With Model 20 August 15, 20013

What happened? 21 August 15, Heating Setpoint Change

Omit Data After Setpoint Change Including Setpoint Change ExcludingSetpoint Change 22 August 15, 20013

When can this method be used? Signal to Noise  Screen using low-cost metrics Name plate RTU kW vs. peak daily premise kW Other trends  Screen using time-series trends in model residuals Does this bias standard protocol  Signal to Noise and other trends are independent of savings  Savings per ton derived from sample of measures that passed screen should be reliable and applicable to program savings estimate 23 August 15, 20013

A second simplified method? What if there is no premise interval meter? Use best practice measurements and models  Unit power metering  Cycling Can we cycle for less than one year?  Proposed to test 60 days starting with each of 12 months 2 30 day periods, 6 months apart, starting with each of 12 months  What periods are feasible in terms of project development When can this method be used  Working economizer  Fans not on auto 24 August 15, 20013

Is there a third Method? Premise interval data with cycling Same limitations as Method 2  Economizer working  Fans not on Auto Additional limitation  Signal to Noise Ratio Requires  Premise interval meter  Cycling like method 2 Advantage  Avoids unit power measurement 25 August 15, 20013

Can fan power be used instead of unit power Would models be biased by excluding measurements of heating and cooling? Can a relationship be derived to estimate unit power from fan power based on the PNNL data? 26 August 15, 20013

Comparison of fan and unit savings 27 August 15, 20013

Guidance on how to proceed Possible protocol strategies  Further analysis of PNNL data Investigate short-term cycling periods Estimating savings from fan power  What is a practical plan for provisional data collection Can we create more test sites from existing projects  Sites with premise interval metering before and after install  Where we could install temporary power metering and turn on cycling Posting PNNL data on RTUG website Would another year of PNNL post (non-cycling data) 28 August 15, 20013