ENERGYPLUS: AN UPDATE

A new building energy simulation program, known as EnergyPlus, was first released in April 2001. Building on the capabilities and features of BLAST and DOE-2, EnergyPlus includes many simulation features that have not been available together in a mainstream building energy simulation program. Some key capabilities include variable time steps, configurable modular systems integrated with heat balance-based zone simulation, multiple comfort models, daylighting and advanced fenestration, multizone airflow, displacement ventilation, flexible system modeling, and photovoltaic and solar thermal simulation. Since EnergyPlus was released in April 2001, more than 24,000 copies have been downloaded. The paper provides an overview of the capabilities and strengths of EnergyPlus in comparison with DOE-2 and BLAST.