CLASSIFICATION: UNCLASSIFIED
I have, sort of. The project has a plant making electricity, using the exhaust to make hot water and an absorption chiller using some of the hot water to make chilled water. I ran in circles trying to figure out the actual plant efficiencies then went crazy trying to gather proof for the leed submittle. It got rejected, twice.... I went mad, got mad, cussed a little.
I ended up using the default efficiencies under 2.4.1.2.3 (see page 13). It ended up changing the energy model by less than 1%. (If I remember correctly)
http://www.usgbc.org/Docs/Archive/General/Docs7671.pdf
So you can spend days and days trying to calculate the actual efficiencies and then another week trying to convince usgbs to accept it, of just use the baseline values.
- Note: I realized that since the building was well insulated, low power density, energy recovery, etc. I realized that even if the default values are less efficient than the actual efficiency, since the majority of the design was focused on using less energy, having that energy created less efficient didn't hurt the values too much.
Note sure if this directly answers your question, maybe the pdf link will be of more help than my answer.
Hi guys,
Thanks for the responses. I have reviewed the central plant guidelines that
the USGBC has written. My main issue was how applicable they would be to my
project, since we are just using a small onsite microturbine and not a large
district system. I think I might be able to come up with an approach based
on the CHP guidelines and see what the reviewer thinks.
Have a great weekend!