New Refrigeration Measures -Status Report- & -Request for Input- September 13, 2010

Acknowledgements We would like to thank the following for their support: Avista Utilities Bonneville Power Administration Puget Sound Energy

3 Agenda Objectives of RTF subcommittee meeting New measure presentation –Floating/Reduced Head Pressure Control for Stand Alone Refrigeration Compressors Next steps

4 Objectives for 9/13 RTF subcommittee meeting Feedback on assumptions and methodology for new measure –Subcommittee questions to be addressed and incorporated into RTF presentation Approval of energy savings analysis approach Support at full 9/28 RTF presentation

Evaporative Pre-cooling for Refrigeration Condensers Barbara Theus Ben Wright

Measure Status Update Modeling and sensitivity analysis complete Further progress postponed until metered data is collected to verify model

Floating Head Pressure Control for Stand Alone Refrigeration Compressors Ben Cartwright Dustin Bailey

Technology Overview This measure requires using controls and/or expansion valve retrofits to change (lower) a fixed head pressure setpoint Allows condenser to operate at a lower temp. depending on ambient conditions and system demand Lower condenser temp. operation = less compressor work, more condenser fan energy Compressor efficiency increases due to discharge pressure decrease

Variable Assumptions

Tornado Diagram

Calculation Methodology/Sensitivity Analysis Baseline eQuest model –Set at “typical” specifications Retrofit case eQuest model –Modified SCT setpoint to 70 F Energy Savings = 607 kWh/compressor hp Holding all other variables at typical value, simulate model changing one variable to min or max. Simulate for each variable.

Sensitivity Analysis Investigation Analyze variable sensitivity –Variables/assumptions from sensitivity analysis output that affect savings most will be investigated Variable savings will be weighted based on sensitivity analysis output Final proposed deemed energy savings computed

Cost – Balance Port TXV $ per evaporator –Valve and labor $ per condenser –Adjustable flood valve, filter drier, bypass valve and labor

Next Steps Confirm and weight savings Determine EUL Finalize costs/hp of compressor Calculate BC ratio

Questions

Next Steps

17 Revisit objectives for 9/13 RTF subcommittee meeting Feedback on assumptions and methodology for new measure Approval of energy savings analysis approach Support at full 9/28 RTF presentation

18 Next steps 9/13-9/20: Address any outstanding questions from RTF subcommittee. 9/20 or sooner: Send final analysis and table to RTF. 9/28: RTF final presentation and request for approval of new measures.

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