Archives

The summary below lists the new features included in earlier releases of EnergyPlus: 7.2.0, 7.1.0, 7.0.0, 6.0.0, 5.0.0, 4.0.0, 3.1.0, 3.0.0, 2.2.0, 2.1.0, 2.0.0, previous versions.

New Features in Version 7.2.0

General

Speed improvements and many bug fixes throughout

Datasets

WindowConstructs.idf was revised so annotations properly reflect U, SHGC, TSOL, TVIS values in EnergyPlus.
FluidPropertiesRefData.idf was revised remove unused superheated specific heat objects. Data sources documented.

Input

Corrected or clarified the units for various input fields.

Windows and Daylighting

New detailed model for complex window systems with Bi-directional Scattering Distribution Functions (BSDF).

Zone and Surface Models

Multiple surface heat transfer algorithms (CTF, CondFD, EMPD, HAMT) can now be used in a single simulation and selected for individual surfaces and constructions
Changed model coefficients for the default outside face surface convection heat transfer correlations called "DOE-2" and "MoWiTT."

HVAC and Refrigeration

Expanded model for Variable Refrigerant Flow (VRF) to allow simultaneous heating and cooling (heat recovery) and water-cooled condensers.
New detailed models for variable-speed DX cooling and heating coils.
Zone sizing expanded to add method for the design supply air temperature to be based on differences with zone temperature.
Detailed ice storage model expanded for inside melt systems to start charging from a bare coil.
HVAC equipment standard rating calculations (Net capacity, SEER, IEER) expanded for multispeed DX coils, multi-speed heat pumps, and packaged variable air volume units.
Improved warning message content when HVAC simulation maximum iterations limit is exceeded.
Added option for non-coincident sizing in HVACTemplate system objects.
Added options for humidity setpoints and desuperheater in HVACTemplate for dedicated outdoor air systems.
Added options for supply air temperatures in HVACTemplate for zone sizing.
Added options for supplementary heating coil to be hot water in HVACTemplates for heatpump and unitary equipment.
Added options for substituting specific chiller, boiler, and cooling tower objects for the defaults normally generated by HVACTemplates.

Controls and User Functions

System availability managers expanded to control operation of additional types of zone equipment including: fan coil units, zone energy recovery ventilators, zone outdoor air units, variable refrigerant flow terminals, and ventilated slabs.
Availability schedule added to daylighting controls.

Utilities

Ep-Launch added controls for multiprocessor behavior when running simulations
IDF Editor enhancements include double precision unit conversions and conversion corrections.
Weather Converter improvements including solar conversions.
Ep-Macro improved to be more robust.

Output

Error messages improved for recurring errors
Tabular reports improved formatting and clean up

Documentation and Guides

Documentation has been updated for all documents.

Platforms

Windows (XP, Vista, Windows 7) 32 and 64 bit versions.
Linux (Ubuntu 12.04 and compatible) 32 and 64 bit versions; RHEL 5.0 compatible available on request via helpdesk.
Mac (10.6, 10.7, and 10.8) 32 bit and (10.7 and 10.8) 64 bit versions
EnergyPlus V 7.2 has been tested on all of these platforms

New Features in Version 7.1.0

General

EnergyPlus can now use multi-core processors to speed execution of models with large geometry descriptions. The solution for inside face surface temperatures was threaded using OpenMP technology.
The Design Day object was restructured and allows finer control over humidity conditions.
The Run Period object was extended to include features useful for real-time and real-weather simulations.

Datasets

New equipment performance data set for 110 different air-cooled chillers—see the file AirCooledChiller.idf.

Input

Corrected or clarified the units for various input fields

Zone and Surface Models

Many new output variables were added to expand the reporting available for surface heat transfer model results.
The modeling of internal gains was revised and improved to facilitate integrating HVAC equipment skin losses and the zone thermal model. Losses from plant pumps can now be added to thermal zones.

Natural and Mechanical Ventilation

New comprehensive modeling of the concentration of a generic gaseous contaminant in zone air including internal emission sources and ventilation controls.
Added system-level zone maximum outdoor air fraction for ventilation rate procedure for sizing and annual calculations.
Added support for multi-path air distribution systems in the ventilation rate procedure based on the ASHRAE Standard 62.1 for annual calculations.
Added Demand Controlled Ventilation for sizing calculations based on ASHRAE Standard 62.1 for both single- and multi-path systems.

HVAC and Refrigeration

Commercial refrigeration models were expanded to include systems that use transcritical CO₂.
A new coil system was added for modeling air-to-air heat pump coils in built-up air handlers, outdoor air systems, and zone outdoor air units.
Fan-powered induction air terminal units can now draw secondary air from plenums.
Added autosizing for hot water baseboards in HVACTemplates.
Added pumping options, piping configurations, fluid types, and additional controls to HVACTemplate plant loops.
Added additional control and part load ratio inputs to HVACTemplate:Plant:Chiller and HVACTemplate:Plant:Boiler.
Added additional error checking to HVACTemplate objects.
Added model for Integral-Collector-Storage (ICS) solar collectors for hot water heating.
Added the ability to use hot water (or steam) coils in various HVAC equipment that have options for different types of heating coils.
The models for adding/removing heat to/from the return air stream were improved to add maximum and minimum limits on the temperature of the return air (+60C, -30C).
The Integrated Part Load Value (IPLV) standard rating for chillers can now be calculated from the chiller input and reported.
Added "High/Low Temperature Heating Standard (Net) Rating Capacity" and HSPF calculation routines for single speed air source heatpumps.
Added two-stage compression with intercooling to the detailed commercial refrigeration cycle model.
New model to reset condenser loop temperature setpoints using predetermined curves that reduce net energy consumption for the chiller and cooling tower plant.
New "ideal" model to reset condenser loop temperature setpoints using a search algorithm to find the near-optimal setpoint at a given timestep which gives the minimum total chiller, cooling tower, chilled water pump and condenser water pump power consumption.
The heat pump water heater model can now use a stratified thermal tank.
Added a new model for variable speed, water-to-air heat pumps.

Controls and User Functions

A new category of HVAC and plant components was added that allow using EMS's capabilities to create user-defined models of new and unique equipment. Users can now define their own component models using new IDF objects that serve as generic holders for zone forced-air units, coils in an air handler, zone air terminal units, or plant components.
The EnergyPlus Runtime Language used for EMS programming was extended to include WHILE loops and to allow directly evaluating curve and table IDF objects from inside programs.
New EMS Actuators were added including: surface construction, surface outside boundary conditions, and refrigeration system condenser minimum temperature limit.
The ExternalInterface used for co-simulation was extended to allow using Functional Mock-up Units (FMU) including a FMU parser for pre-processing FMUs.

Output

Multiple daylight illuminance maps can now be generated for a single zone.
Energy meters have been added to output summary reports.
A new sizing report related to ASHRAE Standard 62.1 has been added to output summary reports

Documentation and Guides

Documentation has been updated for all documents.

Platforms

Windows (XP, Vista, Windows 7) 32 and 64 bit versions.
Linux (Ubuntu 9.04 and above, Redhat 5.4 and above) 32 and 64 bit versions.
Mac (10.6, 10.7) 32 and 64 bit versions.
EnergyPlus V 7.1 has been tested on all of these platforms.

New Features in Version 7.0.0

General

Significant speed increases, most simulations see up to 20% reduction in execution time, depending on features used (also speed increase for many AirflowNetwork simulations and large models with radiant systems–see below).

Datasets

New input data sets for HVAC equipment performance for rooftop packaged air conditioners and heat pumps (see DXCoolingCoil.idf and RooftopPackagedHeatPump.idf).
Extended the library of refrigerant data to include R407a and superheated CO2 properties (see FluidPropertiesRefData.idf).
New input data set for exhaust-fired chiller heater model (see ExhaustFiredChiller.idf).

Input

Steam is now a "built-in" fluid property.
Zone Floor Area can be an input—overrides the calculated amount.

Windows and Daylighting

International Glazing Data Base (IGDB) full spectral data can be used directly.

Zone and Surface Models

Shadowing Model new options: legacy "convex" Weiler-Atherton or Sutherland-Hodgman (more robust for non-convex surfaces).
New input problem checks for surface geometry including: convexity, collinear vertices, planar surfaces, and flipped floors/roofs. For flipped floors/roofs, a fix is attempted.
Conduction Transfer Function model revised to improve modeling of mass-less material layers.
OtherSideCoefficients model extended to provide controlled surface outside temperature with schedule and limits.
Design day weather data generation procedures upgraded for clear sky model and wet-bulb temperature profiles.
Conduction Finite Difference heat transfer model now includes options for solution method and to control node spatial resolution, relaxation factor, and convergence criteria.
Improved convergence checks for initial warmup days.

Natural and Mechanical Ventilation

AirflowNetwork solver enhanced for speed.
Consolidated outdoor air inputs in HVAC models to common design object wherever outdoor air rates are specified.
New proportional control for CO2-based demand controlled ventilation.
New mixing object for door openings into refrigerated zones.
New mechanical ventilation controls based on ASHRAE Standard 62.1 and CEN 15251.

HVAC and Refrigeration

New model for Variable Refrigerant Flow heat pump air conditioning systems.
Ideal loads air system model revised to include outdoor air and economizer controls, humidity control, and capacity limits.
Plant system and component models revised to improve speed and robustness, model fluid properties as a function of temperature and alternative types of fluid, and better flow control.
Glycol mixtures supported in all plant loop components.
New dual duct air terminal unit with dedicated outside air system on one duct and cooling on the other duct.
New absorption chiller model powered by microturbine generator exhaust.
Eliminated redundant input fields in compound HVAC objects.
Added maximum limits for supply air temperature leaving air terminal reheat coils.
Radiant-based HVAC system models revised for significant speed increase when models have a large number of thermal zones.
Low temperature radiant zone HVAC model now includes a "variable off" control mode.
Simple chilled water coil model has enhanced autosizing and variable UA for significant improvements in chilled water flow rate calculations.
New heat transfer models for buried piping systems include interaction with building slabs and basement walls.
Hot water boiler model options for choosing between entering and leaving water temperature as basis in performance curves.
New dedicated outdoor air system HVACTemplate object.
New HVACTemplate options: static pressure reset fan curve, screw chiller type, economizer dewpoint limit, and unitary system design supply temperatures.
New Refrigeration model for cold-storage thermal zones served by refrigeration-based zone units.
Refrigeration condensers now can reject heat to a thermal zone.
Improved Refrigeration model to compare the available temperature of heat reclaimed from a refrigeration condenser to the temperature needed.
Variable speed fan model upgraded to avoid unrealistic leaving temperatures at very low flow rates.

Electrical Systems

New model for chemical battery electrical storage.

Controls and User Functions

Availability Managers extended to work with selected ZoneHVAC equipment including: window air conditioner, unit heater, unit ventilator, packaged terminal air conditioner, packaged terminal heat pump, and zone water source heat pump.
New Setpoint Managers added to: follow outdoor air temperature, follow system node temperature, and follow ground temperature.
Improvements made to how zone equipment is controlled when sequencing multiple devices in a single zone.
New overcool option for Zone and AirLoop HVAC to control high humidity by shifting down the zone cooling setpoint temperature.
Added high humidity control option for air-to-air and water-to-air heat pumps.
New EMS actuators and calling point for custom autosizing of input fields in select DX air handling equipment models.
New EMS actuators for material surface absorptance properties.
New EMS actuators for Variable Refrigerant Flow operating mode and terminal unit part-load ratio.
New EMS actuators for ideal loads air system supply temperature and humidity ratio.
EnergyPlus Runtime Language extended to include built-in functions for generating random numbers, limited support for minus sign, and built-in variables for zone timestep and current environment period.

Output

New thermal comfort reporting based on the adaptive comfort criteria from ASHRAE Standard 55-2010 and CEN 15251.
New Sensible Heat Gain Component tabular report.
New results in Envelope Summary and Lighting Summary tabular reports.
New source energy end use tabular report.

Utilities

IDF Editor enhancements include: (1) search and replace any text in a file, (2) easy node name selection based on names, object, field, or recently used, and (3) expanded validity checking.
New auxiliary tool generates performance curve coefficients for select HVAC equipment.
CSVproc has been reimplemented and is now available as a cross-platform tool.
New EPDrawGUI cross-platform replacement of WinEPDraw.
New IDFVersionUpdater cross-platform replacement of IDFConverter.
Enhanced WeatherConverter with several new features.
EP-Launch can start EPDrawGUI, IDFVersionUpdater, and EP-Compare.

Documentation and Guides

Documentation has been updated for all documents.

Platforms

Windows (XP, Vista, Windows 7) 32 and 64 bit versions.
Linux (Ubuntu 9.04 and above, Redhat 5.4 and above) 32 and 64 bit versions.
Mac (10.6) 32 and 64 bit versions.
EnergyPlus V 7.0 has been tested on all of these platforms.

New Features in Version 6.0.0

General

Significant speed increases, up to 25-40% execution time reduction in most simulations, depending on specific features used.
Revised reference building example files (formerly benchmark buildings).
New detailed 130-zone hospital baseline and low energy example files.

Datasets

New dataset for life cycle costing with regional U.S. fuel escalation factors.
Doubled the number of refrigerated cases in the refrigerated case dataset.

Input

Zone lists supported in most internal gains, infiltration, ventilation, thermostat, and demand manager zone name fields to apply a single input object to multiple zones.
New lookup table object allows alternate performance input format to eliminate the need for regression analysis, can be used in place of existing curve objects, and can create curve objects.

Windows and Daylighting

New reporting of pre-calculated hourly daylight factors.
Allow glazing defined with spectral data to be used with between-glass shades and blinds.
Window 6.3 (fenestration modeling software) will be able to export EnergyPlus IDF segments for window modeling.

Zone and Surface Models

New surface heat transfer convection coefficient options, including adaptive model, many new correlations, and user-defined equations.
Movable outside insulation, with transparent insulation material (TIM) capability, added to conduction finite difference model.
Ecoroof model now has two moisture diffusion calculation methods - simple and advanced.

Natural and Mechanical Ventilation

New comprehensive modeling of CO2 concentrations in zone air, including internal emission sources and ventilation controls.
New simplified model for interactions between mechanical ventilation, infiltration and duct leakage.

HVAC

New separate sizing factors for heating and cooling.
Enhanced Fan Coil model to allow constant water-flow capacity control with multi-speed and variable-speed fan.
Enhanced inputs for variable volume fan minimum power rate.
Enhanced reheat coil sizing.
New component model for central fans with load-dependent power calculations accounting for fan pressure rise variations, duct static pressure reset, and fan, belt, motor, and VFD efficiency variations.
Enhanced hot water coil model with variable UA resulting in significant improvement in hot water flow rate calculations.
New basin heater model added to the single speed, two speed, multi speed and multi mode DX coil models.
New multi-cell feature added for three types of cooling towers: single speed, two-speed, and the variable speed.
New HVACTemplate support for heating/cooling sizing factors, VAV minimum flow rate options, VAV terminal unit controls.

Refrigeration

Multiple refrigeration systems can now share a single condenser.
Refrigeration condenser fan models enhanced and added input for minimum air flow rate.
Refrigeration condenser output enhanced to identify recovered energy used internally for defrost and for other purposes.

Electrical Systems

New transformer model for electrical power service and on-site generation.

Controls and User Functions

New dual-max control for VAV reheat terminal units with reverse acting damper and hot-water coil.
New maximum supply air temperature limit for VAV reheat terminal units.
New averaged setpoint managers allow control of supply temperature and humidity ratio based on requirements of multiple zones.
New setpoint managers that allow control of supply air humidity ratio of a central system serving multiple zones based on the critical zone humidification or dehumidification requirements.
New “All-Off” equipment operation scheme option added for plant and condenser loops.
Weather variables added as energy management system (EMS) actuators.

Economics

New life cycle cost calculations.

Output

New reporting of EER and IEER (in addition to SEER) for DX cooling coils with air cooled condensers.
Enhanced SQLite output to include error file content.

Utilities

New EP-Launch option to run multiple simulations simultaneously, taking advantage of multiple processors (Windows platform only).
Enhanced output file access in EP-Launch (Windows platform only).
IDF Converter (Transition GUI) can now save intermediate versions.

Platforms

Windows (XP, Vista, Windows 7)
Linux (Ubuntu 9.04 and above, Redhat 5.4 and above)
Mac (10.5, 10.6)
EnergyPlus V 6.0 has been tested on all of these platforms.
ParametricPreprocessor executable added to Linux and Mac distribution.

New Features in Version 5.0.0

Datasets

New refrigerated case data set

Input

Slab and Basement preprocessors integrated to run automatically prior to EnergyPlus simulation
New "Unit Type" field for schedules to support units conversions of schedule values
Added ExternalInterface to connect to the Building Controls Virtual Test Bed using Ptolemy

Geometry/Window/Wall/Shading

2-node ConductionFiniteDifferenceSimplified model added

Daylighting

Allow switchable windows like electrochromic windows to continuously dim, instead of only switching to fully dark state. Allows the zone to meet the maximum glare index while providing daylight for spaces

Zone Model

Analytical and Euler solution options for zone air heat balance added

Natural and Mechanical Ventilation

Added minimum outdoor air flow rate operation controls to single and dual duct VAV air terminals
Added maximum supply air flow rate during reheat to single duct VAV air terminal
New object ZoneHVAC:OutdoorAir to describe outdoor air flow rate for use by other objects
New ZoneVentilation:WindandStackOpenArea object calculates ventilation rates based on winds and stack effects
Zone HVAC outdoor air unit module for make-up air and DOAS

HVAC and Refrigeration

Refrigeration loops can now model CO2 secondary loops
Lighting in refrigerated cases revised to better match manufacturer's practices
Zone-side impacts of refrigerant piping heat exchange added
Default 'on' schedules for refrigerated cases and walk-ins added
Dual layer controls for radiant systems removed
Basin heater added to all chillers except absorption chillers
Basin heater added to one and two speed cooling towers
Pumps can ride curves based on pressure
New steam baseboard with radiant heat
New electric radiant/convective baseboard
Added HVACTemplate:Zone:WaterToAirHeatPump and HVACTemplate:Plant:MixedWaterLoop
Standard rating (net) cooling capacity and SEER value reported for single speed DX cooling coil with air-cooled condenser

Electrical Systems

Improved methodology for electric load dispatch via the electric load center

Controls and User Functions

Enhancements to EMS including: system timestep built-in variable, detect unbalanced parentheses in Erl, custom schedule output, and coupling with ExternalInterface
External Interface to the Building Controls Virtual Test Bed (BCVTB) opens EnergyPlus to external programs.

On-Site Energy Supply

Wind turbine module (horizontal and vertical axis turbines)

Output

New predefined output table for DX cooling coils as part of EquipmentSummary report summarize the calculated capacity and SEER values
New simulations database table and tabular reports data added to SQL database output
Added report variables for beam and diffuse solar radiation for blinds
Users can turn off most surface variables to a minimal critical set with single command. Allows tremendous reduction in execution time for large projects with many surfaces

Utilities

New utility EP-Compare allows users to graphically compare results from two simulations
IDF Editor supports IP units in schedules and other objects
EP-Launch, IDF Editor, and WeatherConverter updates throughout

Documentation and Guides

Two new guides: Tips and Tricks Using EnergyPlus, and External Interface Application Guide
Input/Output Reference and Engineering Reference updated and extended for all new features and updates. Total documentation now exceeds 4,700 pages
New translation capability added to EnergyPlus website allows translation into 50 languages

Validation and Testing

New testing report: EnergyPlus Testing with IEA BESTEST Mechanical Equipment & Control Strategies for a Chilled Water and a Hot Water System

Platforms

Windows (XP, Vista, Windows 7)
Linux (Ubuntu 9.04 and above, Redhat 5.4 and above)
Mac (10.5, 10.6)

New Features in Version 4.0.0

Datasets

SandiaPVdata.imf macro data set updated with latest set of input data from SNL for Sandia PV model
Weather (EPW) and stat files now include field for rainfall

Design Day

2009 Design Data
Design day definitions from 2009 HOF are created and used in several input files.

Input

Simple definition of underground walls and floors with C and F factors for code compliance.
Users can now define a window glazing system using U-factor, solar heat gain coefficient (SHGC), and visible transmittance (VT).
Delimiter field added to Schedule:File object.
Switchable windows report variables: switching factor (tint level) and visible transmittance at each time step.
Inputs for parametric preprocessor added including values, logic, run control, and file naming.

Geometry/Window/Wall/Shading

Source sink simulation and variable thermal conductivity property added to Conduction Finite Difference model

Natural and Mechanical Ventilation

Large Horizontal Openings added to AirflowNetwork

HVAC

Plant and Condenser Loops merged with significant improvements throughout.
Walk-in Refrigeration, Refrigeration Cascade Condenser, and Refrigeration Secondary Loop
Evaporative Fluid Cooler
Zone water-to-air heat pump (ZoneHVAC:WaterToAirHeatPump)
Zone air dehumidifier (ZoneHVAC:Dehumidifier:DX)
Plant Pressure Drop can be calculated
Improved convergence tolerance for most unitary systems
Improved control of heat recovery in outside air systems during economizer operation

Controls and User Functions

EnergyManagementSystem implemented, including EnergyPlus runtime language with numerous actuators

Environmental Impacts

Schedules for fuel factors fully implemented in output reporting

Output

Fanger PPD thermal comfort report variable added.
Daylight metrics added: Time Exceeding Daylight Illuminance Setpoint at Ref Point 1 and 2.
Air Node Density can be reported for air nodes.
Infiltration, Mixing, and Ventilation air flow rates may be reported using standard density or current density.
ReportDuringWarmup added to Output:Diagnostics object.

Utilities

ParametricPreprocessor utility creates multiple IDF files from one and varying them parametrically.
IDFConverter utility available -- a GUI for transitioning input files, including converting a list of files, from any older version to any newer version.
Weather Converter can now calculate solar radiation from available data. Improved export and import of .wea (Ecotect) files.
EP-Launch now automatically checks for updated versions of EnergyPlus, it runs the ParametricPreprocessor when necessary, and the utility tab includes IDFConverter.
IDF Editor saves IP/SI view status with each file edited.

Documentation and Guides

Two new application guides: Energy Management System Application Guide and Using EnergyPlus for Compliance.
Input/Output Reference and Engineering Reference updated and extended for all new features and updates. Total documentation now exceeds 4,400 pages.

Validation and Testing

New EnergyPlus testing reports:
- IEA BESTEST In-Depth Ground Coupled Heat Transfer Tests Related to Slab-on-Grade Construction
- IEA BESTEST Multi-Zone Non-Airflow In-Depth Diagnostic Cases MZ320 - MZ360

Platforms

Windows (tested for Windows 7), Linux, Mac (tested for Snow Leopard)

New Features in Version 3.1.0

Input

Users can now define surfaces as simple rectangles (Simple Rectangular Surfaces) for walls, roofs, ceilings, floors, windows, doors, glazed doors, and shading.
New detailed surfaces objects (Wall:Detailed, RoofCeiling:Detailed, FloorDetailed).
InputProcessor can now output defaults, autosizing, and autocalculation statistics.
New Constant Schedule allows simpler schedule definition.

Daylighting

New variables for reporting visual discomfort: Time Exceeding Glare Index Setpoint at Ref Point 1 and Time Exceeding Glare Index Setpoint at Ref Point 2.

Zone Model

Thermochromic windows can now be modeled.
New Adiabatic Surface option for Outside Boundary Condition.
New Sinusoidal option for Other Side Coefficient Boundary Conditions allows users to apply a sinusoidal schedule to the surface boundary conditions.
Two new simplified infiltration models added: Sherman-Grimsrud and AIM-2.
Ventilated slab has additional SerialSlab system configuration option, allowing multiple ventilated slabs in different zones to be connected in series.

Natural and Mechanical Ventilation

UFAD model upgraded.
AirflowNetwork wind speed model for height-dependency improved.
Air Distribution System Model includes more components: heating coil and three heat exchangers.
Demand Control Ventilation model based on ventilation rate procedure of Standard 62.1-2007.

HVAC

New Unitary Air-to-Air Heat Pump and Packaged VAV HVAC Templates.
Improved control of unitary equipment under low-load conditions (Furnaces, Heat Pumps, PTAC, PTHP, and Window AC).
Furnaces/Unitary Systems now allow high humidity control with cycling supply air fan systems.
Cool Beam model added.
Option to size system flow rate and terminal units based on minimum ventilation requirements added; other zone equipment will be sized on zone loads
Fan:OnOff now models multi-speed fan performance.
Minimum stops on VAV terminals with reheat can now be scheduled.
SensibleAndLatent and Desiccant Heat Exchangers now have economizer lockout option.
Revised air-bypass logica for HeatExchanger:AirToAir:FlatPlace to match the logic used for HeatExchanger:AirToAir:SensibleAndLatent.
Refrigeration racks and systems now accept either the name of a case or caselist, and compressor or compressorlist.
Improved moisture condensation controls for Low Temperature Radiant systems.
EvaporativeCooler:Direct:ResearchSpecial model added.
Water consumption model for Indirect Evaporative Cooler extended. Secondary air flow rate can now be autosized.

Output

New tabular reports to support LEED EA Credit 1 forms.
Tabular reports now can be in Inch-Pound units.
Improved diagnostics, warnings, and informative messages throughout.
Output:Reports object converted to simpler Ouput:Surfaces:List, Output:Surfaces:Drawing objects.

Utilities

New AppGPostProcess utility in combination with Building:Compliance object averages the results from four building rotation runs for Standard 90.1 Appendix G compliance.
Datasets can now be directly opened from a menu in IDFEditor.
Weather Converter updated to allow more custom date formats.
Weather Converter now can include rainfall information (where available) in EnergyPlus weather data files.

Documentation and Guides

Input/Output Reference and Engineering Reference updated and extended for all new features and updates. Total documentation now exceeds 4,000 pages.

New Features in Version 3.0.0

Data Sets

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 the EnergyPlusâ€™ 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 existing 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.
Interior 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.
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.
New Compact HVAC objects:
- Packaged single-zone heat pump system (PSZ-HP)
- Packaged variable volume system (PVAVS)
- Constant volume chilled water/hot water system (single-zone and multi-zone)

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.
Standard monthly reports can now be specified by name in the predefined report object without having to include a detailed monthly report object.

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.

Documentation and Guides

Input/Output Reference and Engineering Reference updated and extended for all new features and updates. Total documentation now exceeds 3800 pages.

New Features in Version 2.2.0

Data Sets

Electronic enthalpy air-side economizer curves
Microturbine electric generators

Daylighting

Reference point Illuminance levels calculated by DElight now included in standard output variables.
DElight reference points now show up on DXF outputs.

Design Day

Design days now allow scheduled input for Beam and Diffuse Solar values.
Design days allow users to select periods from weather files to be used in design/sizing calculations.

Input

Example input files created for all new features (More than 245 example input files now available). An additional set of realistic, benchmark files (15) have been added.

Zone Model

Internal gains can now be entered in intensity:
- People can be entered as number of people, people/floor area or vice versa (area/person).
- Lighting can be entered as total Watts, Watts/floor area or Watts/person.
- Equipment (electric, gas, other) can be entered as Watts, Watts/floor area or Watts/person.

Natural and Mechanical Ventilation

Outside Air Controller now allows boosted air flow rates for high humidity control. A schedule may also be used to operate the outside air economizer based on a time-of-day schedule. Each of these features is also included in the controller for the stand-alone energy recovery ventilator.
Infiltration can be entered as total volume, volume/floor area, volume/exterior surface area, or air changes per hour.
Ventilation, mixing and cross mixing can be entered as total volume, volume/floor area, volume/person, or air changes/hour.
Airflow network model now includes more coil types, including water cooling, water heating, detailed flat water cooling, multimode DX cooling, and multispeed cooling and heating.
Multiple infiltration and ventilation objects now allowed in each zone, and the temperature control limits for the ventilation object can now be scheduled (instead of constant).

HVAC

Dual-setpoint humidistat with deadband now available.
Water heater volume and capacity can be autosized.
New desiccant dehumidifier with additional capabilities and flexibility compared to the existing solid desiccant dehumidifier model.
Supply air fan operating mode (continuous versus cycling) can now be scheduled based on time-of-day for window air conditioner, packaged terminal heat pump and water-to-air heat pump.
New economizer controls added to Controller:Outside Air and Controller:Stand Alone ERV objects. New controls include Dew Point Temperature limit and Electronic (Variable) Enthalpy limit.
DX System (DXSystem:Airloop object) now allows cool-reheat dehumidification control type.

On-Site Energy Supply

New operating scheme for electric generators to follow thermal loads.
New microturbine electric generator model.
Upgraded equivalent one-diode PV model to include options for BIPV and inverter.

Environmental Impacts

Environmental emissions can now be scheduled for all fuel types.

Output

New detailed reports on Internal Gains (People, Lights, Equipment) as well as Simple Air Flow (Infiltration, Ventilation, Mixing, Cross Mixing) in the .EIO file.
New report variables for summed zone load components.
Added additional column in internal heat gains reporting that shows the sum of gains/floor area.

Utilities

Many enhancements in the IDF Editor and HVAC Diagramming tools.

Documentation and Guides

Input/Output Reference and Engineering Reference updated and extended for all new features and updates. Total documentation now exceeds 3700 pages.

New Features in Version 2.1.0

Data Sets

Color schemes for DXF (original and default)

Input

Example input files created for all new features (More than 225 example input files now available).

Geometry/Window/Wall/Shading

Surface Surround Subsurface error detection more robust (less false errors)
Autocalculate now allowed for shading surfaces (number of vertices)

Zone Model

Zone sizing calculations now include heat gains from domestic/service hot water uses and water heaters.
User now can choose between ASHRAE Clear Sky and Zhang-Huang solar radiation models for use in design day calculations.

Natural and Mechanical Ventilation

New system availability manager allows system-level control of hybrid ventilation systems.

HVAC

Water-cooled condenser option added to refrigeration compressor racks for useful heat recovery.
Chilled and hot-water coils can now be used in the outside air system to preheat or precool outside air.
New desiccant dehumidifier with additional capabilities and flexibility compared to the existing solid desiccant dehumidifier model.
Water side economizer (including simulation of integrated and non-integrated water side economizers).
Water heater improved for indirect heating (e.g. with remote boiler) and autosizable design flow rates for plant connections.
Packaged terminal air conditioner (PTAC) added to model a fan, DX cooling coil, and a gas, electric, hydronic or steam heating coil serving a single zone.
Multispeed heat pump with up to four discrete speeds for both cooling and heating.
Heat losses (and gains) from plant piping.
New and updated Compact HVAC objects:
- Compact HVAC chilled water coils now use the COIL:WATER:COOLING model by default, COIL:Water:DetailedFlatCooling can be selected as an option.
- Compact HVAC unitary system now supports the draw-thru fan placement option, and allows a schedule for the supply fan operating mode (continuous or cycling).
- New Compact HVAC options for dehumidification and humidification controls for unitary and VAV system types.
- New primary-secondary loop options for Compact HVAC chilled water loops.
Compact HVAC expanded to support specification of outside air as a combination of flow/person, flow/area and flow/zone.
Compact HVAC baseboard heat option added for unitary and VAV zones.
New Compact HVAC objects for unitary heat pump, unitary VAV, packaged terminal air conditioner, and packaged terminal heat pump.

Output

New tabular reports: surface shadowing, shading, lighting, HVAC sizing, system and component sizing, and outside air.
New Report:SurfaceColorScheme allow users to select their own colors for building elements in the DXF output.

Utilities

WeatherConverter now produces KML output (for Google Earth) of latitude, longitude, elevation, and a few climate statistics for locations in a list processing run.
Add comma delimited form of CLM (ESP-r ASCII files) conversion to WeatherConverter.
WinEPDraw produces in new default colors.

Documentation and Guides

Completely rewritten Getting Started manual provides more hands-on example exercises and other information for getting up to speed on EnergyPlus.
Input/Output Reference and Engineering Reference updated and extended for all new features and updates. Total documentation now exceeds 3500 pages.

New Features in Version 2.0.0

Data Sets

New materials data set based on ASHRAE 2005 HOF replaces legacy DOE-2 and BLAST data.
Updated solar collector data set from the SRCC adds 55 more collectors for a total of 173.
Added air change rate to ventilation loads report in StandardReports data set.

Input

Objects and name lengths can now be 100 characters. (Previous limit was 60).
New weather data for 86 locations added: 69 in Australia, 16 in Canada, and 1 in Iran.
Three new unit ventilator input files created: UnitVent5Zone.idf, UnitVent5ZoneAuto.idf, UnitVent5ZoneFixedOANoCoilOpt.idf.
Three new thermal storage example input files created: IceStorage-Parallel.idf, IceStorage-Series-ChillerDownstream.idf, IceStorage-Series-ChillerUpstream.idf.
Example input files created for all new features (More than 225 example files now available)

Geometry/Window/Walls/Shading

Shadowing Calculations object now allows user to specify maximum figures in shadowing overlaps.
Phase change materials (PCM) with variable thermal conductivity and a temperature-enthalpy function incorporated in conduction finite difference solution algorithm.
Basement program now outputs EnergyPlus IDF for wall and floor surface temperatures.
Users can now enter interzone surfaces once and EnergyPlus will automatically create the mirror interzone surface.

Zone Model

Zone Sizing modified to allow standards-type calculation of design outside air flow rates; allows min cooling and max heating limits on design supply air flow rates.

Natural and Mechanical Ventilation

Zone forced air units added to reporting of mechanical ventilation rate and loads
Simple Ventilation object now reports air changes per hour
New options in UnitVentilator include no coil option and fixed amount for outside air control strategy.
AirflowNetwork model can now use Zone Exhaust Fan, OnOff supply fan and the DX heating coil objects.

HVAC

Water-to-air heat pumps now use RegulaFalsi solution technique to improve robustness and to speed up simulation.
Applicability schedule added to System Availability Manager:Low Temperature Turn Off (to support thermal storage).
Evaporative condenser option added to existing refrigerated case compressor racks including availability schedule and basin heater with controls.
Draw-through fan configuration added for furnaces, unitary system and air-to-air heat pumps.
Different supply air flow rates now allowed for cooling, heating and when no cooling or heating is required in unitary, furnace and air-to-air heat pumps.
Common Pipe for Primary-Secondary systems provides an alternative to the Connection component object to model Primary-Secondary systems
Balanced flow desiccant heat exchanger option added for the existing heat exchanger-assisted DX cooling coil object.
Stratified water heater model added.
Uniform load distribution option added to plant load range based operation scheme.
Height-dependent air temperature and wind speed now available for most HVAC systems.

Water Manager

Green roof simulation added.

On-Site Energy Supply

Fuel cell model updated.
Combustion micro cogeneration model added.

Output

Report Variables and Meter Variables (rdd and mdd) separately reported and output as IDF.
Meters can now report cumulative value in addition to resetting at reporting time interval.

Utilities

New EP-Launch utility tab added where users can launch Basement, CalcSoilSurfTemp, CoeffCheck, CoeffConv, Slab and Weather utilities.
CSVproc now supported in EP-Launch.
IDF Editor now preserves the order of user IDFs and includes a large number of other new features.

Documentation and Guides

Input/Output Reference and Engineering Reference updated and extended for all new features and updates. Total documentation now exceeds 3300 pages.