1 / 17

Anti-Sweat Heater Control Small Saver UES Measure

Anti-Sweat Heater Control Small Saver UES Measure. Regional Technical Forum September 17, 2013. Measure Overview. Current Category: Small Saver Current Status: Under Review Current Sunset Date: September, 2013 Reason for Update/Review: Follow-up to recommendation memo

blair-eaton
Télécharger la présentation

Anti-Sweat Heater Control Small Saver UES Measure

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Anti-Sweat Heater ControlSmall Saver UES Measure Regional Technical Forum September 17, 2013

  2. Measure Overview • Current Category: Small Saver • Current Status: Under Review • Current Sunset Date: September, 2013 • Reason for Update/Review: Follow-up to recommendation memo • Subcommittee Review: No

  3. Measure history • Measure moved to “Out-of-compliance” during SBW review in April, 2012 • Research plan proposed by PECI in June, 2013 • Program assessment indicated much smaller potential than originally anticipated • Most of retrofit potential already captured • RTF approved measure category change to Small Saver in June, 2013 with sunset date of September, 2013.

  4. What is an Anti-Sweat Heater (ASH)?

  5. What does ASH Control do? • The power supplied to the ASH is controlled according to store indoor environment conditions • Most often via humidity sensing • Cycles ASH on and off between a range of indoor humidity levels • Typically OFF at 35% RH and full ON at 50% RH • Impacts energy consumption by: • Modulating ASH output kWh • Reducing case cooling load (depending on EER) • Reducing space cooling load (depending on EER) • Increasing space heating load (depending on COP)

  6. Recommendation Memo Items

  7. Recommendation Memo Items

  8. Staff Highlighted Areas • FLH • Estimate of FLH is based on store hours, consistent with case lighting measure • Not to be confused with refrigeration system FLH, which are 8,760 due to using EnergySmart Grocer simulation • Store HVAC Interaction Factors • Added new terms to savings calculation to account for store space heat/cool interaction • Runtime reduction % • Found multiple sources citing range of % reduction

  9. Full Load Hours • Open Workbook • Important to note there are two uses of FLH: • Refrigeration system FLH • Store HVAC system FLH • For refrigeration system, FLH = 8,766 because: • Derive annual EER value from EnergySmart Grocer • Model takes into account part-load operation throughout the year • For HVAC system, FLH = store operation hours • Consistent with LED Reach-in case light measure

  10. Store HVAC Interaction • Open Workbook • Prior savings estimates did not account for this • ASHRAE Journal report shows 65% of ASH heat is released into the store • Many grocery stores heat throughout the year to make-up refrigeration case exfiltration load • Cooling impact is less due to minimal cooling in PNW • HVAC units serving case areas may not need cooling • Contributor to overall savings estimate • Makes up 6-7% of savings using proposed methodology

  11. Estimate for Heating/Cooling HOU • Heating – Broken up by Council climate zones • TMY3 bin hours of heating ≤ 47.5°F • References ORNL waste heat refrigeration study • Adjust upwards by 10°F to account for refrigerated case exfiltration • ASHRAE HVAC-Applications handbook suggests a +10°F contribution for typical grocery store conditions • Can vary greatly. CBSA does not provide more granular data • TMY3 bin hours adjusted to ≤ 57.5°F

  12. Estimate for Heating/Cooling HOU • Cooling – No sources found for cooling HOU • PECI model store data indicates cooling energy use is 11% of total HVAC energy use • Impact on overall savings is small • Suggest using 9% based on professional judgment • Derived using 11% multiplied by heating % and energy use in model store • Ex. 89% heating, 11% cooling energy use for 8760 hours = 72% heating and 9% cooling for mix of actual store hours (8,121)

  13. ASH Runtime Reduction • Differing reductions from various studies • BPA field test: 96% on MT case, 46% on LT case • SCE RTTC lab test: 54% on LT case • Several other citations that vary between 100% and 18% on LT cases • Mostly done in California, though details are vague • Depends heavily on store Relative Humidity • Question is: What are grocery stores typically conditioned to?

  14. ASH Runtime Reduction • Most reports concur that supermarkets are kept at 72°F-75°F and 40%-45% RH • SMUD indicates smaller stores likely in 50%-56% RH range • Less likely to use de-humidification strategies • Suggest using average store operating conditions set at 72°F and 45% RH • Open Workbook

  15. ASH Runtime Reduction • No studies on MT cases other than BPA metering study • Most studies indicate that ASH on MT cases is rare • Assume not needed often in practice, and therefore likely to result in large savings when controlled • Suggest using BPA metered results of a 96% reduction on MT cases due to lack of data

  16. Analysis Results

  17. Decision • “I _______ move to approve the updates to the Anti-Sweat Heater Control small saver UES measure; set the measure status to “Active”; and change the sunset date to September, 2016.”

More Related