Review: S TANDARD P ROTOCOL FOR M EASUREMENT OF F AN AND C OOLING S AVINGS FROM C OMMERCIAL -S ECTOR P ACKAGED R OOFTOP HVAC U NITS Regional Technical Forum February 14, 2012

RTU Savings/MWa – NPCC 6 th Power Plan

RTUs in 6 th Power Plan…

NW Commercial Building Stock Assessment(CBSA) RTU counts-6 th Power Plan AREABIN Average of Count Package RTU Units Average of Pack HVAC Tons Faction of PNW Floor Area Building Count Fraction with RTURTU Count 1. <5, % % 118, ,000-20, % % 151, ,000-50, % % 74, , , %581635% 33, , , %494630% 30, >500, %1755% Grand Total % , % floor area <50kSf Population 64% of buildings <6 tons 79% of buildings <10 tons

PNW RTUs an aging fleet… Age categoryUnder 5 tons5 to 10 tonsOver 10 tons 44%36%20% 0 to 417%30,00024,000 14,000 5 to1032%56,00046,000 26, to 1935%62,00050,000 28, years16%28,00023,000 13,000 51% = 204,000 of the units have been on the roof for over a decade!

RTU Protocol Issues Raised Measure exclusions: which measure are excluded even though not tested? Pre and Post upgrade scheduling: can we do Pre in August and Post in May? Multiple annual site review to better understand confidence interval Cost to implement the protocol needs closer review: cost estimate based on mature program and lessons learned Calculator is for a single unit; sampling protocol is for program evaluation purposes, not unit savings calculations All protocols and calculators will need ongoing RTF support (2013 work plan/budget)

RTU Protocol Confidence Limits Limited Sites Confidence limits are normalized relative to annual energy Confidence limits highest for metering periods starting in late June to mid-July Confidence limits of +- 5% are achieved with metering periods starting in late May and early August

Assessment of 90% Confidence Intervals (West)

Assessment of 90% Confidence Intervals (East)

Nominal 90% Confidence Intervals (East) (Actual coverage rate around 50%)

Nominal 90% Confidence Intervals (West) (Actual coverage rate around 50%)

RTU M&V Field Protocol Purpose Definition of Key Terms Required Knowledge and Skills of Practitioner Required Data Logger Commissioning o One Time Site Measurements and Descriptions o Data Logger Measurements o TMY3 Weather Data Savings Estimation Steps Estimate of Typical Measurement Cost Relationship to Other Protocols and Guidelines Sampling Procedure for Program Evaluation

Purpose Establishes a method by which annual electrical cooling and fan energy use and savings (kWh) can be estimated for a commercial packaged rooftop unit (RTU) optimized for performance including in-field data collection requirements/methods, annualized use/savings calculation method

Definition of Key Terms Baseline Pre Post Commissioning: –data logger/storage/comm equipment –RTU post-upgrade Upgrade Measures

Required Knowledge and Skills of Practitioner Appropriate electrical and related safety procedures Knowing the protocol and calculator Equipment inspection: control points, schedules, cooling stages Logging equipment selection and use Measurement equipment commissioning Ability to interpret results

Required Data Logger Commissioning Communications & data storage True power sampling with current 3-minute interval If site temperature measurement is used, verify temperatures with 2 nd instrument If supply air temperature is used, place away from supply air plenum walls Full data set should be tested immediately Onboard data storage up to 70 3-min interval

Key Measurement Considerations Outdoor air temperature on site or nearby NOAA weather station Supply air temperature optional: for diagnostics, not calculator Timing of measurement: 4 wks pre/4 wks post pre: 3 rd wk May-June; post: 1 st wk August-Sept Timing of retrofit: July

Savings Estimation Automated calculator with true power/temperature data only Sequence of Calculations: Compute the Normalized Annual Consumption (NAC) for pre/post data Energy Savings Calculation Sequence Electric Load Shape Calculation Sequence Demand Savings Calculation Sequence

Estimate of Costs Mature case with lessons learned Expedited approach using NOAA weather for 2 RTUs in same panel = $1250 or $635/RTU Comprehensive approach site weather, 3 RTUs single roof = $2,450 or $817/RTU

Annualized Energy Use / Savings Calculator

Next Steps February 16, 9am-12pm RTUG follow up meeting to Feb 14 RTF review RTF members invited to participate Planning to make final protocol recommendation at March RTF meeting