Is there existing quidance or approved documentation concerning building with a large amount of production based energy use ?
We are in a situation, where the consumption in process would make up to 80-90 % of total energy use.
The basic question is:
- can you include energy saving in the process in the calculation. And if possible, how in the earth can you provide a adequate documentation ?
- can you in some bases limit the amount of process energy to a level, where minimum requirement savings are at least possible?
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Christopher Schaffner
CEO & FounderThe Green Engineer
LEEDuser Expert
963 thumbs up
February 8, 2010 - 12:46 pm
There is currently limited guidance for projects with high process loads. You can include process energy savings in your calculations, but you need to justify VERY CLEARLY, why you feel the savings is justified. Follow the methodology for exceptional calculation measures. Data centers, waste water treatment plants and manufacturing facilities have successfully been certified using this approach.
All energy use must be included. There is currently no procedure that allows any energy consumption to be excluded.
Mike Barker
Principal : Energy / Electrical EngineerBuildingPhysics South Africa
150 thumbs up
February 19, 2010 - 3:57 am
Are there any 2009 NC CIRs - or do 2009 CIRs only apply to projects individually ?
Also, is it acceptable to use waste heat ( say from a data centre next door ) as "free energy" ? Or must it be on-site only ?
David Posada
Integrated Design & LEED SpecialistSERA Architects
LEEDuser Expert
1980 thumbs up
March 25, 2010 - 4:34 pm
Timo, we had a manufacturing facility acheive certification where more than 90% of the facility energy use was from the process loads of the manufacturing equipment. We found a few CIRs that gave some guidance for NC2.2: EA credit 1, CIR Ruling 8/13/2007, Ruling 5/27/2008, and Ruling 2/4/2008.
All energy use, including all process loads have to be accounted for in the model. Reductions in process energy use can contribute to credit acheivement, but since it is not addressed directly by ASHRAE 90.1 we had to create a theoretical baseline for process energy use against which to compare the proposed process. It has been up to the design teams how to create a credible baseline for process loads, but some methods we've seen include comparing the proposed plant's process loads against other similar plants operated by the company, against industry averages, or a manual calculation. In one case the manual caluclation involved comparing the energy consumption of the more efficient proposed equipment with less efficient but commonly available equipment. Savings from high efficiency motors are one place to look, you may even be able to use calculations based on engineering principles that show greater efficiency of one process over another standard practice.
To compare the energy use of the baseline and proposed systems, some teams have used energy use per unit of product produced as a comparison, but reviewers have required all energy savings be converted to back annual energy cost savings. Be careful of calculations that only suggest increased annual production, as this may not be seen as producing annual energy savings. You may need to word your narrative explanation of how the process loads are modeled very thoroughly and carefully, as the assumptions or approach can be misinterpreted.
Lorey Flick
PartnerFlick Engineering Professionals
38 thumbs up
March 30, 2010 - 1:14 pm
I recently filed a refrigerated warehouse facility where a majority of the load was process. In order to document the savings for the process load space (lighting, refrigeration), I had to provide the savings under the exceptional calculation method along with a narrative. My energy model was able to provided the modeling capability for this process load but it had to be broken out separately.
Be very clear in the template which square footage is associated with process loads so the reviewer understands why you selected system x vs y in the base design.