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Presentation - RTF

VIEWS: 0 PAGES: 28

  • pg 1
									Draft Standard Protocol for
 Cooling and Fan Savings
        from RTUs

      RTF March 1, 2011
               RTF-RTUG Time Line

    NEEA                   RTF                  RTF                    RTF
                          Phase I              Phase II               Phase III
    2002-2004
                           2004               2006-2007              2009-2010



                                                          • Test Protocol to Measure
                                                          Savings
• Pilot Field Work
                                                          • Large BPA Field Test
• Inconclusive
                                                          • Goal: Deemed, Deemed
Savings
                         • Secondary                      Calculation or MV Protocol
• Identified potential
                         Source Review                    • Scope Phase IV
deadband issues
• Not ripe for           • Frequency of
Market                   Problems
Transformation           • Scope Next     •   Lab Testing
                         Phase            •   Limited Field Test
                                          •   Honeywell Sensor Redesign
                                          •   Develop Protocol to Measure Savings
                                          •   Scope Next Phase
                                                                           2
      Rooftop Unit Working Group
               Time Line
            RTF             RTF                        RTF                     RTF
          Phase IV         Phase V
                                                      Phase VI               Phase VII
           2011             2012
                                                       2013                    2014


                                                                 •
•Analyze annual data
                           • Implement Roadmap                   • Deep RTU retrofit
• Propose annual savings   elements                              program
estimation methodology
                           •Web-enabled T-stat
• Propose M&V protocol                                           • New gen evaporative
                           approach verified with
• Elements of a regional   2-yr data analysis            •       • Adaptive controls
Strategic Plan/Roadmap     • Premium Ventilation
• New/next generation      benefit established
technology
                                                         • Embedded RTU performance
                           • Stronger                    monitoring/FDD specification
• Recommendation to RTF    regional/national
for next steps             collaboration                 • Test deep retrofit options
• Expand West Coast        • Identify deep retrofit      • Fix DOE2/eQUEST
collaboration              options
                                                                                   3
      Rooftop Unit Working Group
      RTF (End of) Time Line
    Phase XXXIII
       2046



• Dx RTU’s illegal
• Evaporative/hybrids, VRF and ground source heat pumps required by law
• Self-replicating neural networks with self-diagnosing, self-regulating, &
self correcting controls on all units
• Bomb proof economizers/controls
• 7-10 year maintenance intervals
• HVAC OEM’s required to provide performance guarantee over product life
• Cherniack Retires



                                                                          4
Today
nReview Protocol & Calculator
nReview issues raised & addressed at RTUG
nStaff Recommendation
  – Resolve any RTF issues
  – Finalize protocol & calculator under proposed
    guidelines & template
  – Staff to scope task to finalize protocol, test calculator,
    compile documentation and conform to format



                                                           5
      Regional RTU Overview
n Varied programs, participants, utilities and approaches
  across the region

n Project Goal: Protocol for cooling & fan savings
  usable across programs, climates and building types

n Collaborative research sponsored by

   – BPA, ETO, Avista, Idaho Power, RTF

   – Technical analysis by Cadmus, NBI, QuEST,
     Stellar Processes, Ecotope & others

                                                     6
It took a village…




                     7
     The RTUG Process 2010
n7 RTUG Subcommittee meetings
nPrioritized research needed to develop protocol
nCadmus & NBI doing analytics
nFeedback from RTUG Subcommittee
nLots of RTUG participation 20-30 people each
  – In- and out-of-region (CA/NE) participation
  – Other issues taken up too: DCV, Premium
    Ventilation, whole-building approach
                                                  8
                      The Data
PNW RTU 2008-09 Metered RTUs
n Avista = 2 pair side-by-side metered @ 12 months
n BPA RTU Pilot = 161 metered, 24 units @ 12 months
n Energy Trust of Oregon = 13 metered
n Idaho Power = 9 metered @ 12+ months (still going)
>> The nation’s largest, most robust, publicly
           available measured RTU data set
http://www.nwcouncil.org/energy/rtf/subcommitt
  ees/rtug/2009_rooftop/Default.aspx

                                                       9
Current RTU Savings Research
2010-13/ Web-based T-Stats (Dreamwatts)

n BPA 2010 start: 44 RTUs on 3 buildings 24-36
  months DA; Cadmus analysis on first 12 months only
  with report March 2011

n RTF discussion on data analysis for trailing 12-24
  months of BPA units

n Data available to upload to Regional RTU Database

n RTF 2011 start: 3 heat pumps @ 24 months
  w/analysis
                                                  10
           Results for 2010
nSubstantial empirical & analytical basis to
 estimate savings attributable to RTU measures
  – Huge progress has been made!

  – Techniques are being used in impact evaluations

nDeveloped protocol & associated calculator



                                                11
          What Did We Find?
n Accurate measurements require understanding the
  distribution of daily temperatures and proper timing of
  metering
n Differences between hot east side metering and mild
  west side metering
n Measurements of average program savings at 90%
  confidence/10% precision can be achieved
n Buildings exhibit natural changes over a summer:
  ‘building squirm’
n Methodology will pick up any spontaneous building
  operations (squirm) in between pre-post- measurement
  periods                                                   12
     Issue: Highly variable savings

                                                  From BPA 2009




n Probably not deemable UES
n Site-specific savings depend on as-found & program measures
  eg: ETO adding economizers to 3-4 ton RTUs
                                                                  13
Key Elements Addressed by
 Cadmus & NBI & RTUG -1
n Protocol issue raised:
  –Does a single signature accurately show annual energy
  use?

n How issue was resolved:
  –Tested the signature prediction for 10+ months modeled
  data and 10+ months measured data

How issue is expressed in the protocol:
  - The protocol is based on a single signature for
  annualization

                                                      14
               Basic Savings Algorithm
Energy signature based on kWh/day and average daily temp
– Horizontal line = fan energy
– Sloped line = fan + compressor energy
– Balance point = intersection of horizontal and sloped lines
– Use with TMY3 data to annualize energy




                                                          15
 Key Elements Addressed by
  Cadmus & NBI & RTUG-2
n Protocol issue raised:
  –Does the duration of metering affect the accuracy of the
  prediction?

n How issue was resolved:
   Data block analysis was done April – October in 1 week
   increments @ 10, 15, 21, 28 day intervals

How issue is expressed in the protocol:
  - The protocol uses a 4 week measurement interval as
     most accurate; early/late summer intervals produce the
     same performance estimates within a few percent

                                                       16
 Key Elements Addressed by
  Cadmus & NBI & RTUG-3
n Protocol issue raised:
   - Does this method lead to biased predictions?

n How issue was resolved:
  – Examined statistics from the data block analysis that
  showed hot mid-summer data can bias predictions
  especially on the East side

How issue is expressed in the protocol:
  - The protocol recommends not using data from 1st week
  in July through 1st week in August


                                                       17
 Key Elements Addressed by
  Cadmus & NBI & RTUG-4
n Protocol issue raised:
    - Use of of site temperature data vs. recorded hourly data
  from local weather station data

n How issue was resolved:
  – Use of local hourly data was successfully tested as
  source of the temp data for deriving the energy signature

How issue is expressed in the protocol:
  - Protocol recommends use of data from local
  source within limits, otherwise use shielded site-based

                                                        18
 Key Elements Addressed by
  Cadmus & NBI & RTUG-5
n Protocol issue raised:
  – Sample size for M&V to achieve 90% confidence/10%
  precision

n How issue was resolved:
  – Statistic were analyzed to determine sample sizes
      1,000 RTUs:         137
        500 RTUs:         129
       100 RTUs:           88

How issue is expressed in the protocol:
  - The protocol includes a table to guide sample size

                                                         19
Key Elements Addressed by
 Cadmus & NBI & RTUG-6
n Protocol issue raised:
  – Can the annualized protocol be applied to VSD on
  compressor/fans or to VRF technology

n How issue was resolved:
  – No specific work has been done yet, but the approach
    could and should be applied; need method to compare

How issue is expressed in the protocol:
  - Not currently used in the protocol


                                                       20
 Key Elements Addressed by
  Cadmus & NBI & RTUG-7
n Protocol issue raised:
  – How can the field M&V be accomplished at lower cost?

n How issue was resolved:
  – Used nearby weather station data in lieu of site temp
  data; used CT in lieu of true power measurement;

How issue is expressed in the protocol:
  - Adjusted protocol to use these inputs



                                                       21
      Accurate Savings Estimate –
            West/East Sides
n Needs shortest possible measurement intervals to avoid building
  operation changes
n Need 4 week measurement during recommended metering
  window to capture sufficient weekend data
n Pre-measurement window 3rd wk May through 1st week July
n Post-measurement window 2nd wk Aug through 4th wk Sept
n Summer data usually shows no baseload in avg daily –needs to
  be calculated from minute data
n In practice: regressions based hot weather 1st wk July through 1st
  wk August can bias annualized predictions due to limited cool
  weather data (limited or no economizer use)

                                                              22
      Base Load Analysis

nExamined for statistical differences in
 the base load calculation: calculated
 error did not affect sample size

nFound differences due to using more
 power in winter: heating fan energy



 23
                                           23
   Related Non-Protocol Issues
          Not Resolved
n Longevity of fan and t-stat settings
n Air flow issues:
   - How to treat negative savings from upgrade to minimum
     ventilation or ASHRAE 62.1?
  - Programmatic: in field measurement/reset options – use of
      DCV as a proxy?
  - Building code requirement
  - Program benefit-cost issue
n Measure life: 6th Plan = 5 years for O&M?


                                                        24
      Key Elements of Calculator
• RTU power by minute; could be from single calibrated CT

• RTU outside air temperature by hour from site minute data or
  hourly local weather station if acceptable

• RTU supply air temperature by minute; not necessary for
  annual usage estimate, but useful for estimating minimum
  percent OSA

•    Annual histogram for normal average daily temperature at site
    from local TMY data


                                                            25
Key Element: Normalized Annual Output




                                  26
         Key Observations

nProtocol needs graphical data quality review
nProtocol performs annualization &
 normalization
nSignature will show economizer operation
 changes
nThe data should be explicitly segregated by
 weekday and definable weekend
nHourly load shape is available
                                         27
                     Summary
n Protocol ready for finalization including
   –   Resolving any remaining issues
   –   Similar to the 7 protocols under development
   –   Small team with contractor with conforming protocols
   –   Cleaning up calculator
   –   Add ProCost module
   –   Finishing protocol template
   –   Documentation of supporting data & protocol testing
   –   Other conforming details
   –   Bundle up for adoption & publishing
n Staff to scope contract approach & budget
                                                       28

								
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