There are quite a few environmental analysis programs out there for Revit and BIM. My personal favorite is Integrated Environmental Solutions because of its integration with Revit (I will introduce I.E.S. in the upcoming posts).
First, here is a quick intro to Ecotect:
ECOTECT is a complete building design and environmental analysis tool that covers the full range of simulation and analysis functions required to truly understand how a building design will operate and perform. It finally allows designers to work easily in 3D and apply all the tools necessary for an energy efficient and sustainable future. Check out its features to learn more.
Once again, Ecotect is completely free for students who belong to the Autodesk Student Community. I think what I will do is introduce the three major environmental analysis programs within the next few days.
After all of the introductions I will personally compare and contrast the three programs.