Night Covers on Open Vertical Cases

Provisional UES Proposal Presentation to the Regional Technical Forum

August 30, 2011

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Thanks to All Participants

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Measure Summary

• Retrofitting night covers to existing medium temperature open multi-deck cases

• Provisional savings estimate 44 kWh/lin ft and 5 therms/lin ft

• Based on a calibrated DOE2.2r simulation

• Requesting Provisional UES Status

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Measure History• Night Covers (first version):

– Previously RTF-approved: March 2, 2009– Includes separate savings values for applying night

covers to vertical and horizontal refrigerated display cases

– Calculation methodology: uncalibrated engineering calculations

• Vertical Night Covers– Updated UES to replace existing value, which is out-

of-compliance

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UES Analysis Summary

Appendix A: Provisional UES Checklist

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Appendix B: UES Measure Summary

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Implementation and Product Standards

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• No night cover may be present in baseline

• Minimum 1 year manufacturer’s warranty

• Minimum application of 6 hours/ 24 hour period

Estimation Procedure

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• Modeled using DOE 2.2R to capture interactive effects

• “Typical” store was built using GrocerSmart Audit Data

• Multiplex Baseline assumes Floating Head Pressure, T8 lamps, and EC motors are in place.

• Stand-alone system baseline assumes T8 lamps and EC motors.

• Infiltration, conduction, and radiation load based on manufacturer data, the ASHRAE Refrigeration Handbook, and SCE lab test report

Model Calibration: Whole Building

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Model Calibration:Compressor Energy Use

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Model Calibration- Baseline:Case Refrigeration Load

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Total case load based on ANSI/ASHRAE 72 testing = 1600 btu/hr-ft

ASHRAE data used to disaggregate load components

Model Calibration- Efficient Case: Case Refrigeration Load

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Cost Estimates

• Cost estimate: $36/ft

• Unchanged from previously accepted cost value

• Supported by invoice levels observed by program

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Measure Effective Useful Life

• EUL: 5 years

• Unchanged from previously accepted EUL

• Supported by 1 year warranty requirement

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Reliable Efficient Case Data

Calibration Plan• Collect Metered Data

– Rack: Volts, Amps, PF– Condenser: Volts, Amps, PF– Hourly Natural Gas via Utility Interval Meter– Hourly Outside Air Temperature

• Minimum 3 weeks baseline • Minimum 3-weeks post

– This is a direct load measure. We expect less seasonal interaction than system measures like floating head pressure.

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Calibration Plan• Develop regressions for daily or hourly

refrigeration use correlated to ambient temperature

• Annualize using TMY data– Pre, Post and Savings (Pre minus Post)

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Calibration Plan

• Collect DOE2.2r inputs per data collection specifications• Use inputs to run DOE2.2r for Baseline & Post estimates

of total refrigeration energy• Compare estimates of Baseline, Post & Savings

estimates of refrigeration energy to best-practice estimates

• Modify DOE2.2r models and iterate tests until both baseline energy use, post energy use and energy savings at all sites are reasonable and there is no significant bias.

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Proposed Provisional UES Value

Measure

Site Savings (kWh)

Site Savings (therms)

Measure Life

(years)

Capital Cost

($/unit)

TRC B/C

Ratio

Night Covers- Retrofit to Open Vertical Case on Multiplex - Seattle, WA 42.0 5.5 5 $36 1.5

Night Covers- Retrofit to Open Vertical Case on Stand-alone - Seattle, WA 44.7 5.5 5 $36 1.6

Night Covers- Retrofit to Open Vertical Case on Multiplex - Spokane, WA 41.6 5.2 5 $36 1.5

Night Covers- Retrofit to Open Vertical Case on Stand-alone - Spokane, WA 44.0 5.2 5 $36 1.5

Night Covers- Retrofit to Open Vertical Case on Multiplex - Billings, MT 45.7 4.9 5 $36 1.5

Night Covers- Retrofit to Open Vertical Case on Stand-alone - Billings, MT 47.8 4.9 5 $36 1.6

Night Covers- Retrofit to Open Vertical Case - Average 44.3 5.2 5 $36 1.6

RTF Proposed Motion:

“I _________ move that the RTF approve the UES for Night covers on Open Vertical Refrigerated Display Cases under provisional status with a sunset date of August 31st, 2013.