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EnergyPlus

Version 9.1.0
31 March 2019
EnergyPlus is a trademark of the US Department of Energy.

What it is, What it is not

EnergyPlus is a simulation program designed for modeling buildings with all their associated heating, cooling, lighting, ventilating, and other energy flows. EnergyPlus is a stand-alone simulation engine without a ‘user friendly’ graphical interface . . . EnergyPlus reads input and writes output as text files.

Utilities and tools for creating, editing, and running input files that come with EnergyPlus include IDF Editor and EP-Launch. Many graphical user interfaces for EnergyPlus are available or under development. For the latest tools, please see this website for third party interfaces. Some of these may produce out of date IDF files; you can then use the IDFVersionUpdater program to convert older files to current EnergyPlus version (you may need to use the Multiple Version Conversions set – see below.

What’s going on in V9.1?

Will there be any considerable difference between version 9.0 and 9.1?

How about IDF and IDD? Do they remain unchanged?

Is version 9.1 backward compatible? Can I run v9.0 file in v9.1?

In addition, as happens in every EnergyPlus release, there are new checks on user input. Even if your file ran in an earlier version, it may not run in the newer version after conversion due to newer checks on the validity of input.

Multiple Version Conversions

The install includes the IDFVersionUpdater program and the necessary programs to convert from the previous version (including .rvi and .mvi files) to the current version. For older versions, you will need to visit the helpdesk and download the multiple conversion set of programs. The HelpDesk downloads area: Converting Older Files will contain the necessary readmes and zip/tar files of programs to convert IDFs from V1.0 to the current version.

Documentation

The EnergyPlus documentation is included in pdf form in the installer. The pdfs are also available online. Big Ladder Software is also hosting html versions of the EnergyPlus Documentation online

There are some other documents of interest available on the web site including:

Weather Data

A small subset of weather files that are available on the web site are also installed in the WeatherData folder. EnergyPlus uses these files directly for annual simulations. The Weather Converter program that is part of EnergyPlus can read these weather files and provide .csv (comma separated variable) as well as statistics reports about the included (or other) files. Weather data for more than 2100 locations in more than 100 countries can be downloaded on the EnergyPlus Weather Page.

Highlights of this release (V9.1.0)

The highlights – improved and new features – are displayed by category.

Core changes to EnergyPlus

There were many bug fixes and new features added for this release. Some new features were still added, check the installed changelog file for full details.

General

Prominent New Features

PR # Description
6192 JSON (and CBOR/MessagePack) Tabular and Timeseries Outputs
6766 An EIR Formulated Water-to-Water Heat Pump Model
7028 Fix #5982 - add hyperlinks to classes in I/O Ref
7040 Heat Emissions from Buildings to Ambient
7045 Add Resource Properties to Windows Binaries and Cleanup CMake Rules
7062 Various HVACTemplate fixes including new fan coil control and coil options
7065 Add Resource Properties to Windows Binaries (continued)
7094 Hybrid Model: Zone Infiltration and People Count
7098 EnergyPlus Essentials document
7100 Adds End-Use Subcategory field for Pumps
7171 Sequential Load Fractions on ZoneHVAC:EquipmentList
7202 Sync Kiva convection algorithms with EnergyPlus user-specified algorithm
7209 Add 90.1 2016 test models

Runtime Performance Enhancing Developments

PR # Description
7141 Cleanup and Refactoring of Plant Structures
7146 Stratified tank refactor for performance

Platforms

And many other enhancements throughout.

Installation contents

The installation creates a program folder with icons/shortcuts for the programs/files in EnergyPlus that can be accessed from Windows menus, including removing EnergyPlus from your system. In Windows OS, these will be available from the “Programs” area in the Start Menu. Note that only a few of the programs will store anything in your Windows\System directory (IDFEditor, EPLaunch, WeatherConverter).

Known problems

While every effort has been made to clean up all the “defects” that have occurred during our testing, quite a few known (and even more unknown) probably remain. Specifics on the remaining known problems can be found on the GitHub repository issues page. If you are interested in what has been addressed, the issues resolved in this release are installed similarly in the changelog.

Thanks

Special thanks to our beta testers for this release.

Thanks for downloading EnergyPlus. If you did not download the previous version, we welcome you. If you are a returning customer, we hope you find the latest release exceeding your expectations.

We look forward to serving you!

EnergyPlus Development, Testing, and Support Team

Additional steps you may want to consider:

  1. Download additional Weather Data for use in running example files or your files.

  2. The helpdesk (energyplus.helpserve.com) is the primary support site. The helpdesk site requires a login via self-registration or via sending a problem/question to the email address. Go to the helpdesk site or send a support request to: email address of EnergyPlus-Support@gard.com. In addition to having support tickets and responses from helpdesk personnel, there are knowledgebase articles, download area and news subscription or viewing.

  3. Join the EnergyPlus_Support email group at YahooGroups: We have established an email group to foster user-to-user discussion as well as maintain an archive of information for EnergyPlus users. The files area will allow for uploads of specific files though attachments to email are also allowed. The main page for the group is at: groups.yahoo.com/group/EnergyPlus_Support.To subscribe, send an email message to: EnergyPlus_Support-subscribe@yahoogroups.com

  4. BLDG-SIM: A free e-mail list for all building energy simulation program users to ask questions to other users. See lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org for information on joining this email list.

  5. Open-Source License (or distribution license): Licenses for the source code and distribution are available from the website: Licensing Info

If you have any other questions, contact EnergyPlus Support.

Copyright © 1996-2019 The Board of Trustees of the University of Illinois, The Regents of the University of California through Ernest Orlando Lawrence Berkeley National Laboratory, Oak Ridge National Laboratory, managed by UT-Battelle, Alliance for Sustainable Energy, LLC, and other contributors. All rights reserved.

Other Notices and Acknowledgments are found in the Acknowledgments document.