This seems related to this post: https://unmethours.com/question/10240/where-are-the-default-chiller-curve-coefficient-coming-from-in-os/ but I think it's different enough to warrant its own question. The gist is that it seems that the default air-cooled chiller EIR-fPLR chiller curve doesn't seem to be representative of most chillers, or any reasonable default.
The EIR-fPLR curve assigned to an air-cooled chiller when you pull it out of the library has the following coefficients:
a 1.6853121,
b -0.9993443,
c 0.3140322,
This curve looks nothing like any of the curves in the EnergyPlus Air-Cooled chiller library or any of the Comnet or DOE-2 default curves. According to this curve, chiller energy usage will actually increase as PLR decreases, which is obviously incorrect. Seems like there must be a reference off somewhere? The CAPFT and EIRFT default curves look very similar to those of the other curves I can find. I'm using OS version 1.12.0, but looking at an old version of the library from 1.11.0, I think the default EIRfPLR curve is the same. Is this a mistake in the library?
I'm attaching chart graph comparing the EIRfPLR curve evaluated compared to the DOE-2 and Comnet default curves that Julien Marrec posted in the question linked above. As you can see, they're pretty drastically different!
