New Version of EnergyPlus Building Energy Simulation Program Now Available

April 29, 2005

The newest version of EnergyPlus (Version 1.2.2) was completed in April 2005 and is now available in versions for both Windows and Linux operating systems. EnergyPlus Version 1.2.2 can be downloaded at no cost from EERE's Building Technologies Program Web site:

What's New in Version 1.2.2?

New features include:

  • modeling of ventilated photovoltaic roof and other cladding systems¬†
  • natural cross ventilation
  • simplified definition of HVAC systems
  • refrigerated casework
  • variable speed cooling towers
  • link to SPARK to simulate complex equipment and systems not in EnergyPlus
  • more than 2,200 pages of documentation and speed improvements throughout.

For a complete list of new features added in this and previous versions, visit

User Interfaces

Three interfaces for EnergyPlus are available. EP-Quick creates an EnergyPlus input file based on a broad range of zone templates. EP-Quick was released in April 2005. E2AC is an interface in Portuguese available in a beta version (since January 2005). An English version of E2AC is planned in the next few months. DesignBuilder is a full-featured interface available in a beta version. Several other interfaces are under development. Watch the Building Technologies Program Web site for up-to-date information on these and other interfaces.

EnergyPlus Weather Data

More than 240 weather files have been added to EERE's EnergyPlus Web site since the last release. Weather data for more than 900 locations in 100 countries are available on the EnergyPlus Web site: