Hi, I'm a newbie who's interested in green industry. I'm trying to figure out what are the widely used energy modeling software, daylight, ventilation and those related software in U.S. Can someone help me?

Thank you

For residential buildings BeOpt is a popular energy modeling tool that can be downloaded at no cost.

https://beopt.nrel.gov/

ResCheck is a national software used by most of the governmental agencies for permitting, I like to model with REVIT by AutoDesk

For modeling I use Google sketchup. A free download and their daylight/ shadow studies are dead accurate in my case.