Anyone,
For a project applying the 2005 "LEED NC App Guide for Multiple Buildings...." (AGMBC), I'm trying to determine the system/plant for the models of individual buildings on a new campus served by it's own new CUP. The results from these models are then to be averaged or aggregated into one PRM calculation for the project/campus. They also are used to document EAp2.
One suggestion I've been given is that the right approach for the proposed models is to scale down the characteristics of central plant for each of the building models. The baseline system/plants for the individual buildings would be determined by a standard application of the PRM for the building use/size. This seems similar to but not exactly the approach of Option 2 of the DES guide. Some old CIRs endorse this method for slightly different scenarios. It also seems that this would be the most appropriate way to "use a weighted average for the group of buildings based on their conditioned square footage, or aggregate the data into one PRM calculation," as the EAc1 section of the AGMBC instructs.
Can anyone confirm this approach or offer an accepted alternative? If I can help it, I'd rather not wait for, or pay for an interpretation right now.
In the section for EAc1 Supplementary Guidance, the AGMBC states first that "the buildings are rated based upon the energy (and its cost) that crosses the building boundary," and then that "Calculation instructions for Version 2.1 and 2.2 will be supplied as supplements to the respective Reference Guides." I The only "calculation instructions," I can find are the "District Energy Guidelines." The current 2010 AGMBC does not address this at all. The use of buildings plural, and then building singular confuses me. Each "building" is served by CHW and steam, but the "buildings/project/campus) are served by electric and gas.
The DES guidelines apparently do not apply: Section 2.2 "Exception: When buildings are part of single LEED project, the CUP is a DES only if it is expected to serve other buildings not within the LEED project boundary." Since the project CUP serves only projects within the LEED project boundary, this CUP is apparently not a "DES" in LEED land.
Thank you
Fred Porter
