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Small Compressed Air Analysis Tool. Summary of Subcommittee Meeting Presented to the Regional Technical Forum on January 6, 2008. Background. Compressed air savings calculator developed by Cascade Energy Engineering
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Small Compressed Air Analysis Tool Summary of Subcommittee Meeting Presented to the Regional Technical Forum on January 6, 2008
Background • Compressed air savings calculator developed by Cascade Energy Engineering • Proposal at the Nov 2008 RTF meeting was to allow the calculator to be used in lieu of more detailed M&V to determine savings for systems under 75 hp • RTF asked for real-world data to verify calculator works properly
Subcommittee Meeting – 12/18/08 • Attendees (conference call) • Jeff Brooks • Chris Helmers • Tom Osborn • Greg Kelleher • Joel Jackson • Paul Warila • Al Frazer • Eric Brateng • Adam Hadley
Subcommittee Meeting Materials • Memo: QEI Energy Management Inc (John Shinn) to Pacific Corp (11/13/08) • Tool should ask for rated input bhp; tool should include an efficiency penalty for VFD’s; Tool should correct compressor’s flow for operating pressure • “The baseline power is developed from the percent load with the equation of the performance curve for the compressor with the components for the equations coming from various look-up tables. The slope and intercepts are reasonable for the various compressor types. I think the author handled the VFD minimum power dilemma very well…” • “ The accuracy of the tool will depend in a large part on the percent flow in the ‘profile of compressed air demand’ table. My concern is that most plants will not be able to fill this out accurately. I imagine a manual of some type will come with the tool and the manual will provide some quantitative and non-quantitative methods for estimating these part-load values.” • “Since you have a great deal riding on the user’s ability to correctly use this tool, I would not give it to anyone until they have had a training class...” • Memo: EWEB Review of Regional Compressed Air Calculator • “We found the analysis to be generally accurate, but have a few comments.” • “We feel the Achilles Heel of the calculator is the ‘profile of compressed air demand’ input table…it is critical we find a way to reduce the potential for errors in the inputs…ways to mitigate this error – for example: training, help screens, user manuals.” • “It’s not possible to go back and estimate demand profiles on a compressor that has already been replaced. Using the monitored data to ‘guess’ a profile would, by default, bias the results toward over-predicting the accuracy.” • Cascade Energy Engineering’s “sensitivity checks” (next two slides)
Sensitivity Check – Inlet Mod Provided by Cascade Energy Engineering
Sensitivity Check – Load/Unload Provided by Cascade Energy Engineering
Subcommittee Recommendation to RTF • The subcommittee believes the calculator provides reasonable outputs, if reasonable inputs are provided. • The RTF subcommittee recommends that the RTF allow the use of the compressed air tool to determine energy savings (in lieu of M&V) for compressed air systems 75 horsepower and less. • The calculator should be used by qualified users and all calculator inputs should be reviewed by a utility engineer or program provider. • The calculator will be modified to provide space for the user to provide a description of how the "profile of compressed air demand" was derived.