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Grocery Store Issues. RTF April 10, 2007. Need Recommendations PECI: Energy Smart Grocer Program. Savings method for interactive measures Unitized savings using simplified methodology Load shapes for savings Measure lives Sub Committee to: Scope out evaluation plan & protocols
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Grocery Store Issues RTF April 10, 2007
Need RecommendationsPECI: Energy Smart Grocer Program • Savings method for interactive measures • Unitized savings using simplified methodology • Load shapes for savings • Measure lives • Sub Committee to: • Scope out evaluation plan & protocols • Design empirical testing for Auto-closer, Door Gasket, Strip Curtains
Measure Savings • PECI calculator reviewed by Cascade Engineering and RTF sub committee • Eight recommendations for improvement • Seven adopted plus other improvements • Final Cascade recommendation to review • Some new measures not reviewed by Cascade • Review of savings for unitized measures
Interactive Measures • Segue to slides from PECI • PECIInteractiveAdjust.ppt
Unitized Savings • 36 Measures with simplified unit savings • Savings derived from calculations • Used for measures with relatively consistent savings • Little value to model savings • Savings per unit and number of units • Example: kWh / linear foot case * linear feet case • Methods reviewed by Cascade Engineering & RTF staff • Comparative analysis in: ESG Measures.xls\Measures
Unitized Savings Issues • Savings for anti-sweat heaters in medium temp • Assumptions for door auto-closer savings • Savings & methodology for door gaskets • Assumptions and methods for strip curtains • Review comparative analysis in: • ESG Measures.xls\Measures
Unitized Savings: Anti-Sweat Heater Control • Turn off resistance heaters when not needed • Humidity or timer control • Compared PECI savings estimates to BPA findings on NRM installations • Comparable for low-temp cases • PECI savings low for medium temp (46 versus 330 kWh per year per linear foot case) • Post-install duty cycle differences
Unitized Savings: Auto Closers • Assures door gets closed if left open or ajar • Door intentionally open 3 hours per day (1095/year) • Ajar 25% of remaining hours (1915/year) • Savings based on closing door these hours • Heat loss by ASHRAE Open Door Method • Effective opening approx 3 to 4 inch opening • No comprehensive data on door openings • BPA data on two cafeteria walk-ins show much lower opening times (one hour/day & .29 hour/day)
Unitized Savings: Gaskets • Damaged gaskets = infiltration • Hours 8760 minus open time minus ajar time • 5750 hours for gasket savings • Gasket prevents 2% of open door heat loss • ASHRAE Open Door (2006 Chap 13.4 equation 12) • PECI revised savings downward 12-25% • Ambient conditions, door size, effectiveness • Savings now maximum of 2% of case load
Unitized Savings: Strip Curtains • No savings in BPA program due to uncertainty • Monitored data on one store showed increase energy use • Evaluate first • PECI Method: • ASHRAE Open Door Heat Loss • 80 percent effective • Door open hours: Survey or default (0.4, 0.8, 1.2 hrs/day) • Issues: • Is door left open longer due to curtains? • Longevity of curtains
Load Shape for Savings • Need shape for cost-effectiveness analysis • Few previously-existing shapes for refrigeration • Proposal: Six new shapes • Developed by engineering assumptions, DOE2.2R refrigeration runs, and some metered data • Reviewed by NRM, PECI, kW Engineering
Refrigeration Load Shapes • GrocRefLoad • GrocRefUnLoad • GrocFloatHeadAir • GrocFloatHeadEvap • GrocNightCover • GrocAutoCloser • GrocDoorGasket See Grocery Shapes.xls for map of measures & corresponding load shapes and derivation of shapes
GrocRefLoad • Follows shape of refrigeration load • Responds to ambient conditions at heat sink • Based on DOE2 model runs for 8760 hours • Tested impact of climate (Boise & Seattle) • Tested impact of heat sink (Air & Water Cooled) • Tested control type (Fixed & Floating Head) • Result: • Total savings change with factors • But shape of load remarkably similar • Proposal: Simple average of 8 cases
GrocRefLoad Link to excel
GrocRefUnLoad • Shape is opposite refrigeration load • Savings occur when refrigeration load is reduced • Unloading compressors or condenser fans with VSD or floating suction • Turn off walk-in evap fans when compressor is off • Shape derived from compressor cycling data
GrocFloatHead • Floating head pressure control • Source DOE2 runs • Average for climate, system type & heat sink • Similar to GroceryUnLoad, but steeper • Small savings in summer • Little difference by climate • Significant difference Air-Cooled versus Evap-Cooled • Proposal: Two shapes Air-Cooled & Evap Cooled
New Load Shapes (3) • GrocNightCover • GrocAutoCloser • GrocDoorGasket
Measure Lives • Gaskets 4 • Night Covers 5 • Auto-closers 8 • Anti-Sweat Heater Control (8 or 12?) • ECM Motors (12 or 15?) • New Efficient cases 12 • Condensers 10 • VFD Refrig Motor 10 • Multiplex systems 15 • Floating Head Systems 16 • Case Lighting (12 or 16?) For Details: ESG Measures.xls
Need RecommendationsPECI: Energy Smart Grocer Program • Savings method for interactive measures • Unitized savings using simplified methodology • Load shapes for savings • Measure lives • Sub Committee to: • Scope out evaluation plan & protocols • Design empirical testing for Auto-closer, Door Gasket, Strip Curtains