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Energy analysis using Revit

asked 2018-10-24 03:31:31 -0600

cooper86's avatar

Hello, I'm very new in this type of project and I'm having a lot of trouble trying to do energy analysis with E + using a model in Revit, so, I would like to ask for advice about the best method to do the energy analysis using Revit instead of OpenStudio, or at least, trying not to use OS as intermediate step.

The biggest problem I'm having so far is Revit creates analytical surfaces and spaces, and run the first analysis using Insight where from I get the IDF file and then run the simulation with EnergyPlus. With that file E+ generate many errors with non-convex surfaces and other type of warnings and severe error always causes of surfaces, especially FenestrationSurface:Detailed, and sometimes with non encloser zone completely. I have also discovered that when I update the IDF from 8.5 to 9.0 version of E +, it does not recognize any windows I have in my Revit file.

So, at this point, I do not know how to fix the surfaces problems using only Revit. So my question is if it is possible do the analysis with Revit and E+ or if on the contrary I have to use OpenS because Revit as a tool to model energy analysis is not a complete tool and it's necessary the use of OS.

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answered 2018-10-28 17:30:32 -0600

updated 2018-10-28 17:34:54 -0600

It sounds like you don't have very clean geometry. Where does your geometry come from? Is it an architect's model? If your geometry isn't well enclosed and built to be an analytical model, it won't work. From my experience, Revit can't really create analytical model geometry from an architectural model, even if they say they can. There are exceptions, but that is the rule.

I've used Revit for energy modelling geometry many times, but have always drawn my own geometry from scratch, using the architects model as an underlay. In this way, you create your own analytical surfaces, use boundary lines if splitting open spaces, and then place your own spaces. It's critical to have the space properties set with the upper limit as the level above and the limit offset as 0. If you forgot to do this its always easy to change in a space schedule.

You also need to be careful to create spaces that are as simplified as possible. And use a window object in Revit that has no framing included, just a simple glazing surface. You don't want all the extra detailed surfaces.

This tutorial is specifically for translating gbxml geometry from Revit to IES, but the rules are the same if you are staying in Revit. I think this is a good place to start:

Here is an image from a model I've created, I don't have an image of the entire model, but this can give you an idea of what the simplified version should look like: image description

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Could you tell me something? What version of E+ do you normally use? Because in my case, I update the idf version from 8.5 to 9.0 and despite the simulation finish with many error, the mayor problem is that E+ don't recognise any windows surfaces, even if the model is as simple as yours.

cooper86's avatar cooper86  ( 2019-03-12 01:16:24 -0600 )edit

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Asked: 2018-10-24 03:31:31 -0600

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Last updated: Oct 28 '18