Evaluation of Energy Savings for Strip Curtains Presented To RTF Scott Moore PECI Sr. Engineer June 2, 2009

2 Presentation Overview Justification for laboratory testing Methodology for laboratory tests Review test results Discuss potential annual savings and BC ratios Provide overview of current CPUC/ ADM Associates strip curtain evaluation

3 Justification For Laboratory Testing All known savings results prior to 2007 were calculations based on ASHRAE infiltration formulas BPA conducted field M&V testing in 2007 –Pre and post strip curtain test runs –Inconsistent door open times between test runs –Energy data not normalized for weather or differences in length of defrost –Inconclusive results –BPA conducted field M&V testing in 2007 BPA and PECI concurred on laboratory testing to control variables

4 PECI Test Overview Emerson Sidney, Ohio Test Laboratory Separate Low and Medium temperature tests 12 hour runs –Closed door –Open door with strip curtains –Open door without strip curtains

5 Test Walk In Box / Condensing Unit

6 Evaporator Coil Location

7 Indoor Condensing Unit Location

8 Average Medium Temp Run Conditions 38F internal temperature 74-75F D.B. / 61-63F W.B F condenser air inlet 27.4 sq. ft door Open door 4 minutes every 2 hours Consistent with BPA for auto closer / gasket / strip tests

9 Average Low Temp Run Conditions -4F internal temperature 75-77F D.B. / 53-54F W.B F condenser air inlet 27.4 sq. ft door Open door 4 minutes every 2 hours Consistent with BPA for auto closer / gasket / strip tests

10 Medium Temp Emerson Results (12 hr. test data converted to 24 hr. results) ParameterDoor Closed Door Openings w/Strip Curtains Door Openings w/o Strip Curtains Condensate Drainage per Day (oz) Duty Cycle (%) 6.9%8.0%9.4% Average Power (Watts) Hour Energy (kW-hrs) Energy increase per day (kW-hrs) -0.9Baseline3 % energy increase -4.6%Baseline15.2% Annual Energy Savings w/ curtains (kWh) 1095 Annual Energy Savings Per Sq. Ft Door (kWh) 40

11 Low Temp Emerson Results (12 hr. test data converted to 24 hr. results) ParameterDoor ClosedStrip Curtain No Strip Curtain Condensate Drainage per Day (oz.) Duty Cycle (%) Average Power (Watts) Hour Energy (kW-hrs) Energy increase per day (kW-hrs) -4Baseline13.7 % energy increase -6.5%Baseline22.2% Annual Energy Savings (kWh) 5001 Annual Energy Savings per Sq. Ft. Door (kWh) 182.5

12 Application of Lab results for Utility Measure Unscaled Variable = Door open time Scaled Variables = Door open time Compressor system type and EER Climate zone

13 Annual Energy Savings / Sq. Ft. Opening (Unscaled) Medium Temp: 0.8 hr open (48 minute lab test): 40 kWh 1 hr. open: 50 kWh 2 hr. open: 100 kWh 2.5 hr. open: 125 kWh 3 hr. open: 150 kWh 4 hr. open: 200 kWh Low Temp: 0.8 hr. open: kWh 1 hr. open: 228 kWh 2 hr. open: 456 kWh 2.5 hr. open: 570 kWh 3 hr. open: 684 kWh 4 hr open: 912 kWh

14 Determination Of Potential Scaled Annual Savings For BPA Territory Determine door open time standard Adjust test results for system type, EER and annual outdoor ambient conditions –Multiplex system (FHP, FSP) –Single system (fixed head pressure) –Varying climate zones –Control systems

15 Door Open Times Logged data from BPA Field tests for walk in box strip curtains and auto door closures: –18 logged boxes –Per day range: 0.6 hrs hrs. –Per day average: 2.5 hours

16 Compressor System Weighting % BPA Walk-in Load attached to System Type System TypeLowMedium Integral1% Multiplex57%59% Stand Alone42%40%

17 Final Lab Results Weighting Factors for Northwest Medium Temp: 77%* Low Temp: 82%* *Accounts for population of different compressor system types, EER’s and climate zones

18 Potential Savings* Medium Temp. Box Annual Savings: kWh/sq.ft./hr * door open hours * weighting factor = 50 * 2.5 * 0.77 = 96 kWh/sq. ft Low Temp. Box Annual Savings: kWh/sq.ft./hr * door open hours * weighting factor = 228 * 2.5 * 0.82 = 467 kWh/sq. ft * Based on 2.5 hr. open/day/365days/yr.

19 Potential Savings (Weighted by population of box type) PECI Grocer Smart ECM motor database –73% Medium temp boxes –27% Low temp boxes 96 kWh/sq. ft (med.) * 0.73 = 70.0 kWh 467 kWh/sq. ft. (low) * 0.27 = kWh = 196 kWh Combined low/med weighted savings = 196 kWh/sq. ft.

20 BC Ratio / TRC Levelized Cost Input $10.00 sq. ft. total 2008 installed cost $9.55 sq. ft. total deflated installed cost 4 year Measure Life No annual maintenance

21 BC Ratio / TRC Levelized Cost* TypeB/C RatioTRC Levelized Cost Med Low Combo *$10.00/ sq. ft. total install cost, deflated to $9.55/ sq. ft. * 4 Year Measure Life

22 CPUC / ADM Study ADM Associates is lead contractor for strip curtain study for the CPUC ADM research concluded: –Previous savings numbers calculated by various state utilities –Previous work paper savings based on calculations using ASHRAE infiltration guidelines and formulas –No field M&V or logging of door open times

23 ADM Proposal For Analysis Domain of study –Type of business –Type of refrigeration unit –Geographical location of site Develop a site sample design –Paired study –With strip curtains –Without strip curtains

24 ADM M&V Approach Use statistical model Conduct tracer gas measurements of air infiltration Calculate loads based on refrigeration system weather dependant COP Log system energy use Conduct door monitoring with data loggers –Number of openings –Length of openings

25 Questions / Comments