Could Room Area Differ b/n MEP and IES??

[s.messing]

Hello everybody!

Quick question that has me stumped. Someone in the office is running an energy analysis on a typical floor plate. There is simply a central core and an external office (I know this is not realistic, but this is not part of the question).
In Revit MEP 2008, the user has a core of 400 square meters and an external (surrounding) doughnut of 2100 square meters (for a total of 2500 square meters). Somehow, after hitting the Heating and Cooling Loads button, and running through the initial calcs, the IES (embedded in MEP) tells the user that the area is 2887 square meters! :?:
See the attached screen shots. Anyone have a simple reason that IES would give back a completely different square footage number than MEP???

Thanks in advance for suggestions, advice, etc.

Cheers,
Stephen

[kyle.bernhardt]

Stephen,
Most likely this is the "Room in a Room" scenario, which would result in such a result. Rooms are defined by a "circuit" which defines the outside boundary of the Room itself. If there is a Room completely inside of that boundary issues arise. This is a limitation of how Rooms are defined in the gbXML schema and is common to all software that produces such a file (to the best of my knowledge).

We cover this matter in the Limitations section of our Green Paper (http://images.autodesk.com/adsk/files/building_performance_analysis_using_revit.pdf). The solution is to define the Room boundary to include the inner room by using Room Seperation Lines...assuming this is the problem. Otherwise your best bet would be to log this issue with our support team so we can look at the model.

HTH,
Kyle B

[s.messing]

Thanks Kyle,

You caught me right where one should never be: asking a question and having the information/ answer right in front of my nose. I skimmed the White Paper on Revit and IES and didn't notice the room inside a room situation. My next door neighbor asked me if I could explain the error. I tried to figure it out for a couple of minutes, couldn't, and then posted. Amateur error on my part, but a valuable learning experience anyway.
Now, after having read the White Paper very carefully several times, my list of questions has diminished significantly.

Thanks for your help and guidance. Your work is not going unnoticed.

Cheers,
Stephen

[kyle.bernhardt]

Always glad to help.

:beer:
Kyle