DOE simulation software
DOE-2 is a widely used and accepted freeware building energy analysis program that can predict the energy use and cost for all types of buildings. DOE-2 uses a description of the building layout, constructions, operating schedules, conditioning systems (lighting, HVAC, etc.) and utility rates provided by the user, along with weather data, to perform an hourly simulation of the building and to estimate utility bills. The “plain” DOE-2 program is a “DOS box” or “batch” program which requires substantial experience to learn to use effectively while offering researchers and experts significant flexibility; eQUEST is a complete interactive Windows implementation of the DOE-2 program with added wizards and graphic displays to aid in the use of DOE-2.
Freeware: YESMore info & download: http://doe2.com/DOE2/index.html