The latest release of the EnergyPlus building energy simulation program,
Version 3.0, was completed on November 13, 2008 and is now available in
versions for both the Windows and Linux operating systems. (Macintosh
version will be available within a few days.) A few key new
features include ventilated slab, fully-coupled 1-D finite
element heat and moisture transport model, thermal chimney,
CoolTower, additional detailed refrigeration component
models, DC-to-AC inverter and simple battery, and
direct output to SQLite. We have updated and extended capabilities
throughout the existing building envelope, daylighting, and HVAC
equipment and systems portions of the program.
EnergyPlus V 3.0 is available at no cost from the EnergyPlus web
site:
www.energyplus.gov.
Energy Design Plugin for Google SketchUp: The
Energy
Design Plugin is a free plugin for the GoogleSketchUp 3D drawing
program. The plugin makes it easy to create and edit the building
geometry in your EnergyPlus input files. The plugin also allows you to
launch EnergyPlus simulations and view the results without leaving
SketchUp.
EnergyPlus Example File Generator: A Web-based service is
available that creates and runs EnergyPlus input files for simple models
of commercial buildings. The input files (and annual results summary
files) are sent to your e-mail address as attachments. This is a pilot
project and is currently made available only as a BETA service. You can
access the service and customize the characteristics of the building you
want to model on the
EnergyPlus Example File
Generator Application (pop-ups must be enabled).
The set of example input files now includes full-blown models of typical
new construction (drawn from the DOE Commercial Benchmarks project).
What's New in Version 3.0?
Datasets
· Refrigerant properties
for R404a, R410a, and R507a added to the refrigerant database.
· New library of
compressor performance curves for refrigeration systems created.
· New performance curves
for condensing and high-temperature boilers.
· California Title 24
Time Dependent Valuation (TDV) factor schedules (2008) dataset
added.
· California Title 24
operating schedules dataset added.
Input
· Version 3.0 includes
widespread changes to input syntax. The complete set of input objects was
revised to make EnergyPlus?s input ?language? more consistent, logical,
and informative. Although the majority of words used to describe input
object names, field names and key choices have changed, the underlying
meanings remain the same. (Yes, this will require substantial changes to
input data files--aided by the Transition program which can be accessed
through the EP-Launch utility.)
· New examples input
files for all new features.
Zone Model
· New Ventilated Slab
model includes radiant heating and cooling interactions with hollow core
slabs
· Infiltration models now
allow air flow rate per unit of exterior wall area as an optional
input.
· Pipe heat transfer
loads added into zone air heat balance calculations.
· New optional algorithms
for fully-coupled, 1-D finite element heat and moisture transport model
for simulating the movement and storage of heat & moisture in and
through building surfaces.
· Moisture transfer
function and moisture finite difference models removed.
· The algorithm for
variable system timestep was revised. Changes include uniform system
timestep length across zone timestep and stricter management of history
terms for zone air conditions.
Natural and Mechanical Ventilation
· Additional hybrid
(mixed-mode) ventilation controls added to allow global control of
surface openings based on master zone, limit opening levels based on wind
speed, and allow control of Mixing and Ventilation objects.
· Temperature limit
controls added to Mixing and Cross-Mixing objects.
· New Thermal Chimney
model added--uses solar radiation to enhance natural ventilation.
· New CoolTower model
added--uses natural evaporative cooling to cool incoming air.
· Added new outside air
minimum and maximum fractions to easily model 100% (or any fixed value)
OA systems, leakage or stuck OA dampers.
HVAC
· Refrigeration system
capabilities expanded with more detailed component models. Users can now
simulate: (1) variable evaporating temperatures, (2) variable condensing
temperatures, (3) mechanical subcoolers that transfer refrigeration loads
from less efficient low- temperature systems to more efficient
medium-temperature systems, and (4) liquid suction subcoolers.
· Improved error trapping
for refrigerant and glycol properties at extreme temperatures and
pressures.
· Single-speed cooling
towers can now use fluid bypass as capacity control, saving water but
requiring more fan energy.
· New linear curve to
complement other curve objects.
· Absorption chiller now
can connect to steam or hot water loop.
· Enhanced absorption
chiller model added.
· Radiant-convective
baseboard model added.
· Boiler model upgraded
to include performance curve which accounts for load as function of
operating temperatures.
· Set Point Managers now
test for control node conflicts.
· New system availability
managers added: Scheduled On, and Scheduled Off.
· New Underground Pipe
object added; upgraded Pipe Heat Transfer objects.
· New Fluid Cooler
objects added--single and two-speed dry cooling towers for hydronic
loops.
· Component sizing
factors added for boilers, chillers, and cooling towers.
· Added chilled water
thermal storage tank models for both mixed and stratified tanks.
On-Site Energy Supply
· PV model restructured
to separately model inverters and storage systems.
· DC-to-AC inverter model
added along with simple battery model.
· Simple
Photovoltaic-Thermal model added for pre-heating outside air and hot
water heating.
Economics
· Energy cost
calculations now includes real time pricing, minimum monthly charge, and
buy/sell/net metering as new inputs
· A new monetary unit
object (Currency Type) added
· Additional economic
reporting of energy and demand for each charge
Output
· SQLite added as another
output format option, providing optional export of time-series results
directly to database.
Utilities
· EP-Launch now handles
blank weather files as if no weather file is specified in group
simulations.
· IDF Editor new features
include wrapping long text strings over multiple lines within cells,
required fields now shown with blue field names, and added recently used
file list.
· WinEPDraw can be used
with older (pre V3) files as well as V3 files - if placed in the proper
folder.
Documentation and Guides
· Input/Output Reference
and Engineering Reference updated and extended for all new features and
updates and renaming. Total documentation now exceeds 3800
pages.
And many other enhancements and speed improvements throughout.
See
http://www.energyplus.gov/features.html for a complete list of
new features added in this and previous versions. Suggestion: get as much memory as possible in your computer for
running EnergyPlus. A recent team upgrade from 1.8GHZ machine with
768MB memory to a 2.1GHZ machine with 2GB memory caused one file to go
from a full annual simulation (5 zones) at about 8 minutes to a 2-1/4
minute run on the newer machine.
Update on User Interfaces and Tools?
Many user interfaces that create and run EnergyPlus input files and
display results graphically are available (Demand Response Quick
Assessment Tool, DesignBuilder, Easy EnergyPlus, EFEN, Hevacomp, and
HLCP) and under development (ComFen, TREATPlus and EPlusInterface).
Check our web site
(
http://www.energyplus.gov/ep_interfaces.html ) for up-to-date
information on these and other interfaces.
Utilities and tools for creating, editing, and running input files that
come with EnergyPlus include IDF Editor, EP-Launch, and HVAC-Diagram (see
http://www.energyplus.gov/ep_utilities.html ). Third party tools for
creating, editing, and displaying EnergyPlus input files are also
available, including DrawBDL, EcoTect, EnergyPlugged, ESP-r, Green
Building Studio, EzDrawPlus, IFCtoIDF, TSe+, and EzPlus-Parm. See
http://www.energyplus.gov/third_party_tools.html for more
information.
EnergyPlus Training Workshops
We will continue to offer training workshops throughout 2008 and
2009. For more information, please see:
http://www.gard.com/training.htm
What?s going on in V3.0.0?
Will there be any considerable difference between version 2.2 and
3.0? Yes.... and no. The basic structure of EnergyPlus is still
as it has been but there are some significant changes that you will want
to be aware of.
As always, there are a number of new features and bug fixes. The
highlights of features for this version are listed belowsee
www.energyplus.gov/features.html for a complete list of new features
added in this and previous versions. How about IDF and IDD? Do they remain unchanged? There has been a whole scale revamping of the IDD/IDF naming
structure and the names of most objects and key values have changed. Your
best option is to use the included Transition program if you want to use
any older version files. Is version 3.0 backward compatible? Can I run v2.2 file in v3.0?
See previous item. There are many changes that require you to use
the transition program for V3.0. EP-Launch can check the selected file
(if there is a version object) and you can launch the Transition program
from the EP-Launch ?File? menu. You can also view the
ObjectStatus spreadsheet in the
root folder of the installed version. This file has detailed explanations
of changes to the objects. There is also a new option for the transition
program that allows you to supply a list of files and it will convert
them for you. The transition program is described more fully in the
Auxiliary
Programs document. In addition, we can make available a zip file of
all transitions programs and batch files such that files can be taken
from much earlier versions to current version.
EnergyPlus Weather Data
Weather data for more than 2000 locations worldwide are available on the
EnergyPlus web site:
http://www.energyplus.gov/cfm/weather_data.cfm (This
includes a new weather data set for New Zealand. New data for China
and Australia should be available soon.)
If you know of other weather data for your country that you'd be willing
to share with the EnergyPlus user community, please contact Dru Crawley
(Drury.Crawley@xxxxxxxxxx
).
EnergyPlus Helpdesk
A helpdesk system has been set up for managing EnergyPlus user
support requests. The helpdesk system includes a download area, a
knowledge base and troubleshooting area. To submit new support requests
(tickets) or search the knowledge base, please go to
energyplus.helpserve.com
. You may also submit new issues, files and reply to tickets via
e-mail at
EnergyPlus-Support@xxxxxxxx. This address has been linked to the
helpdesk since early May 2008. This is the best way to get your
specific EnergyPlus questions answered.
EnergyPlus_Support Group at YahooGroups
Are you a commercial or academic user of EnergyPlus? Join more than
1800 EnergyPlus users in the user-to-user email group on YahooGroupsa
place to ask questions and share information with other EnergyPlus users.
The YahooGroup also provides a searchable archive of all 7+ years of
discussion. You can also upload files to share with other users. While
the EnergyPlus development team does monitor the YahooGroup list, the
best place for individualized support is the
EnergyPlus Helpdesk.
To subscribe, send an email message to:
EnergyPlus_Support-subscribe@xxxxxxxxxxxxxxx
If you hate to constantly receive email, you can edit your YahooGroup
membership to only send a daily digest of messages.
Building Energy Simulation User News
Want to keep up to date on EnergyPlus and other building simulation
tools? Subscribe to the bi-monthly electronic newsletter for users of
EnergyPlus, DOE-2, BLAST, GenOpt, SPARK, and Energy-10. See
http://simulationresearch.lbl.gov/un.html
BLDG-SIM
Join the free e-mail list for users of all building energy simulation
programs. Ask other knowledgeable simulation program users your
questions--about EnergyPlus and other simulation programs. See
http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
for information on joining this email list.