Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I think the answer to which is the best program to use always wind down to three things: 1) preferences and 2) what you are trying to achieve and 3) given the budget and the human resources (familiarity).
I'm replying to your question in the context of doing LEED and T24 only. Other type of analysis (parametric, box modelling, component modelling)... that's another day of discussion on its own. Ranking in term of my personal preference, it would be: (hate to love) CBECC-COM, Epro, Open Studio, IES.
IES VE generating results are not as straight forward, several clicks vs one click for OS or EPro, so that's one of the con I don't like about it. I like using IES VE for geometry as well, so we usually just export to CBECC-com to clean up the things that are buggy with IES-T24 module.
But overall, to build T24 and LEED model altogether using this software or that.... it's probably:
I haven't have a reason to use OS over IES-VE other than refrigeration system, eventually need to go down to the IDF editor for E+. But I imagine OS would be more useful at the city-level modeling since there's linkage with 3D warehouse , but there's the sad disconnect from Google Earth. >:( OS is also better if you replicate similar model over and over again. IES Run time can be tedious if you have to click 3 runs to get results. I'm quite fond of the OS measures as well, but have not explore better how it can be better utilized to fasten the LEED / T24 purposes quite yet beside probably QC purposes. Otherwise, most software have the template idea. IES-VE ASHRAE 62.1 interface to integrate with the ApacheHVAC is pretty awesome. The Table for the Zone (the excel-looking one) is also pretty awesome for internal QC. Those features are hard for OS to win over for day to day modeling.
As a reviewer, Open Studio / E+ standard results are pretty easy to review, which is nice. Since that's all you get sometimes, and not the model itself. Have not received IES model to review via incentive program so I can't say much here, but from submitting IES-results reports and what not, it's a little harder to put together into a review-friendly template without doing that Excel magic.
So eh, preferences.
