by Brianna Crandall — November 12, 2018 — The US Department of Energy (DOE) and the national labs have released updated versions of their state-of-the-art, open-source, whole-building energy modeling tools: the EnergyPlus engine and the OpenStudio software development kit (SDK) and application.
According to the DOE website, whole-building energy modeling (BEM) is a versatile, multipurpose tool that is used in new building and retrofit design, code compliance, green certification, qualification for tax credits and utility incentives, and real-time building control. BEM is also used in large-scale analyses to develop building energy-efficiency codes and inform policy decisions.
EnergyPlus is a whole-building energy simulation program that engineers, architects, and researchers use to model both energy consumption — for heating, cooling, ventilation, lighting and plug and process loads — and water use in buildings. Historically focused on commercial buildings, EnergyPlus has recently been expanded with modeling capabilities relevant to residential buildings and data centers.
Although the increment in the major version number from EnergyPlus 8.9.0 to EnergyPlus 9.0.1 (yes, there is already one post-release bug fix!) suggests wholesale changes that fundamentally break backward compatibility with previous versions, EnergyPlus 9.0.1 is a traditional update that resolves bugs and issues — over 70 have been resolved in this release — while adding new features.
New features include:
- WinCalc engine integration
- ASHRAE Fan Energy Index (FEI) calculations
- Inclusion of fan heat in cooling coil sizing calculations
- AirflowNetwork enhancements to allow multiple primary air loops
OpenStudio is a cross-platform (Windows, Mac, and Linux) collection of software tools to support whole-building energy modeling using EnergyPlus and advanced daylight analysis using Radiance. OpenStudio is an open-source (LGPL) project to facilitate community development, extension, and private-sector adoption. OpenStudio includes graphical interfaces along with a Software Development Kit (SDK).
OpenStudio 2.7.0 is available and, as with all recent releases, it supports the most recent EnergyPlus version, 9.0.1. The new release includes improvements to the Application Programming Interface (API), Command Line Interface (CLI), and the OpenStudio Standards gem.
New feature highlights include:
- API access to multiple HVAC air-loops per zone
- API access to ExternalFile and ScheduleFile objects
- CLI access to custom Ruby gems
- OpenStudio Server enhancements for Resque job-queuing environments
- Miscellaneous OpenStudio Standards fixes and new feature for commercial prototype building models
The release also resolves over 70 bugs and issues. A full list of new features and resolved issues is available with the release notes.
Both EnergyPlus and OpenStudio are available for Windows, Mac OS X, and Linux Ubuntu platforms. Source-code is available from the respective GitHub sites, as is bug and issue reporting and tracking, as well as new feature suggestion, discussion, and voting. Peer-to-peer and developer support is provided via the forum. Dedicated support is available via these providers.