EnergyPlus Example File Generator Help

How It Works

The web-based forms allow you to enter general information about the building you want to model.  The application then automatically creates a complete EnergyPlus input file, runs an annual simulation, and then emails you the EnergyPlus input, output, DXF and other files along with an annual summary of the energy results.  Because EnergyPlus input files contain a lot of detail, the building description has been reduced to a set of simple, high-level parameters.  The remaining detail is generated from defaults, building energy standards, and computer routines that automatically generate a complete geometry description.  This beta application is a spin-off of commercial building research and is therefore currently only available for commercial buildings.

Model

(Simple, Detailed)There are two methods for entering model information: Simple and Detailed.  Your choice of method will determine which parameters you can access and change.  The Simple method has the fewest parameters while the Detailed method has the most.  Each method has a separate input form with its own set of parameters.The Simple method represents a building that is constructed according to the energy performance standard that you select.  The Simple method is intended to be used to obtain a baseline or basecase model for subsequent comparisons.You can switch between input forms at any time, but input data may be lost when switching from the Detailed method to the Simple method.

Instructions-Simple

The Simple Method represents a building that is constructed according to the minimum energy code standard that you select. This model requires few inputs because nearly all options are defaulted or determined by the standard. Results from the Simple Model can be compared to the Detailed Model to get an indication of energy savings.

Instructions-Detailed

The Detailed Method allows you to access all available parameters.

Targeted Standard

This is the building energy performance Standard.  The choice of standard determines many of the defaults and assumptions that go into the simulation model.  The standards available from this service are based on those for commercial buildings published by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) and on the International Code Council (ICC). ASHRAE 90.1-2007 is ANSI/ASHRAE/IESNA Standard 90.1-2007: Energy Standard for Buildings Except Low-Rise Residential Buildings. Atlanta, GA: ASHRAE. ASHRAE 90.1-2004 is ANSI/ASHRAE/IESNA Standard 90.1-2004: Energy Standard for Buildings Except Low-Rise Residential Buildings.  Atlanta, GA: ASHRAE. ASHRAE 90.1-2001 is ANSI/ASHRAE/IESNA Standard 90.1-2001: Energy Standard for Buildings Except Low-Rise Residential Buildings.  Atlanta, GA: ASHRAE. ASHRAE 90.1-1999 is ANSI/ASHRAE/IESNA Standard 90.1-1999: Energy Standard for Buildings Except Low-Rise Residential Buildings.  Atlanta, GA: ASHRAE. Low Energy Case: The Low Energy Case is a example version that attempts to reduce the building energy use according to best practices by adding overhangs, reducing lighting power densities, increasing system efficiencies, and other various techniques. 30% Guide is Advanced Energy Design Guide for Small Office Buildings.  Atlanta, GA: American Society of Heating, Refrigerating, and Air-Conditioning Engineers. (2004)

 

This drop-down selects the type of Units accepted for all of the input fields.  S-I and I-P units are currently supported for all inputs.  The output results, however, are currently only available in S-I units.

Email

We require your Email Address so that we can deliver your EnergyPlus input file and simulation results.  You will receive two emails.  The first acknowledges that we received your request and the second will contain the input file and results as attachments.

Location

Location is an important parameter.  The state and city fields are directly mapped to one of the Typical Metereological Year (TMY2) weather files.  The location also determines the ASHRAE climate zone for code requirements, as well as local utility tariff rates. If your location does not exist in the list, try to select a city that is near your site or has similar weather conditions.

Building Description

The Building Description is used to help identify simulations.  The description will be used in the subject of the emails along with the building name in the result files.

Total Floor Area

This parameter specifies the Total Floor Area of the building.  The Total Floor Area is used in conjunction with the Number of Floors to determine the overall geometry of the building envelope.  The Basecase Model assumes a building with a square footprint.  Each floor is automatically divided into four perimeters zones and one core zone.(Only used with Basecase)

Number of Floors

This parameter specifies the Number of Floors that will be modeled for the building.  Below-grade floors and basements are not currently modeled.  If the building has more than three floors, the example file generator will produce a model with just three floors where the middle floor is multiplied to represent the additional floors.  (This is done for faster execution.)

Roof Type

The Roof Type is the type of roof that will be modeled for the building.  The roof types consist of different material layers and have different performances depending on the Standard selected.  The types of roofs available are insulation entirely above deck, metal building, and attic and other.

Wall Type

The Wall Type is the type of wall that will be modeled for the building.  The wall types consist of different material layers and have different performances depending on the Standard selected.  The types of walls available are mass, steel-framed, metal building, and wood-framed and other.

Geometry Configuration

The Geometry Configuration determines the overall geometry of the building's footprint and envelope.There are six geometry configurations available.  The diagrams on the input form show the basic form of the floor plate or footprint that each configuration provides.  In the case of multistory buildings, each floor will have the same configuration.  The configurations available include the following:Rectangular automatically generates a square or rectangular building with the specified Number of Floors and specified dimensions listed in Geometry Parameters.  Each floor is either a single thermal zone or divided into four perimeters zones and one core zone, depending on the Zone Layout.  The Geometry Parameters that need to be given values include Length 1 and Width 1. Courtyard automatically generates a square or rectangular building with an inner courtyard that is open to exterior environment.  Each floor is either four or twelve thermal zones depending on the Zone Layout.  The Geometry Parameters that need to be given values include Length 1, Length 2, Width 1, and Width 2.L-Shape automatically generates a building with a L-shaped plan.  Each floor is either three or eight thermal zones depending on the Zone Layout.  The Geometry Parameters that need to be given values include Length 1, Width 1, End 1, and End 2.H-Shape automatically generates a building with a H-shaped plan.  Each floor is either three or fifteen thermal zones depending on the Zone Layout.  The Geometry Parameters that need to be given values include Length 1, Width 1, Width 2, End 1, End 2, Offset 1, Offset 2 and Offset 3.T-Shape automatically generates a building with a T-shaped plan.  Each floor is either two or ten thermal zones depending on the Zone Layout.  The Geometry Parameters that need to be given values include Length 1, Length 2, End 1, End 2, and Offset 1.U-Shape automatically generates a building with a U-shaped plan.  Each floor is either three or eleven thermal zones depending on the Zone Layout. The Geometry Parameters that need to be given values include Length 1, Width 1, Width 2, End 1, End 2, and Offset 1.

Zone Layout

Zone Layout refers to how the building is divided into thermal zones.  Thermal zones are a fundamental part of building energy simulation and can be thought of as rooms or collections of rooms inside the building that have similar thermal loads, share a common thermostat, or are served by the same HVAC system.  Thermal zoning is not an exact science and there are many different approaches that are valid.  Therefore, there are two levels of detail available on the input form: "Minimum Zones" and "Perimeter and Core Zone."  The pattern of thermal zoning varies with Geometry Configuration and is best understood by studying the diagrams on the input form.  The diagrams show the geometry configuration with the thermal zone pattern within the footprint.  "Minimum Zones" is recommended for smaller buildings and/or faster simulations.  "Perimeter and Core Zones" is recommended for larger buildings, modeling daylighting controls, and improved accuracy.

Geometry Parameters

The Geometry Parameters define the key linear dimensions of the building.  The horizontal dimensions are best defined by studying the diagrams to the left of the Geometry Parameters.  The parameters that apply to each Geometry Configuration will vary.The Floor to Floor Height defines the vertical dimension as floor-to-ceiling height for each floor and works with the Number of Floors to determine the total building height.

Orientation

The Orientation of the building defines the angle between the building's y-axis and true north in the clockwise direction in degrees.  A rotation of 180 degrees flips the building around so that the north (or back) facade is facing south (or front).

Building Type (Principal Building Activity)

The Building Type is a classification system used by CBECS called Principal Building Activity.  Selecting a Building Type defaults the values for People Density, Plug Intensity, Lighting Power Density, and Exterior Lighting.  It also determines the set of schedules included in the model.  If the fields are displayed, they can be overridden.  CBECS is the 1999 Commercial Buildings Energy Consumption Survey: Consumption and Expenditures Tables.  Washington, DC: Energy Information Agency.

People Density

The People Density parameter specifies the number of occupants per floor area.  People Density is a peak value.  The number of people at a given time is adjusted by occupancy schedules that are determined by the Building Type.

Electrical Plug Intensity

The Plug Intensity parameter specifies the electrical power of plug and equipment loads per floor area.  Plug Density is a peak value.  The electrical power at a given time is adjusted by operation schedules that are determined by the Building Type.

Gas Appliance Intensity

The Gas Appliance Intensity parameter specifies the power of natural-gas fueled appliances such as ovens.  Intensity is a peak value.  The gas use rate at a given time is adjusted by operation schedules that are determined by the Building Type.

Light Intensity

The Light Intensity parameter specifies the electrical power of ambient lighting per floor area.  Light Intensity is a peak value.  The lighting power at a given time is adjusted by operation schedules that are determined by the Building Type.  The lighting power can also be reduced by automatic dimming controls if the Daylighting Illuminance Setpoint is greater than zero.

Exterior Lighting

The Exterior Lighting parameter specifies the exterior lighting power per linear length of the building perimeter.  All exterior lights are assumed to have automatic photocell controls that only turn on at night.

Glazing Percentage

The Glazing Percentage parameters specify the percentage of the exterior wall area that is covered with windows.  Glazing Percentage is specified separately for Front, Left, Right, and Back facades.  The facade orientations are defined before any rotations from the Orientation field.  So if Orientation is set to zero, then "Front" is South, "Left" is West, "Right" is East, and "Back" is North. Windows are added in horizontal bands that stretch the entire length of each exterior wall.  The height of the window is calculated to match the Glazing Percentage.  The properties of the windows are determined by the standard and the climate zone inferred from the Building Location.

Overhang

Overhangs are horizontal, fixed exterior shades over the windows that are defined by the Projection Factor and Offset fields.  Projection Factor specifies how far the overhang projects out from the wall that anchors it as a fraction of the window height.  Offset specifies the vertical distance from the top of the window to the overhang as a fraction of the window height.  Overhangs stretch the entire length of each exterior wall.  Overhangs are specified separately for Front, Left, Right, and Back facades.

Fin

Fins are vertical, fixed exterior shades along the windows that are defined by the Projection Factor and Offset fields.  Projection Factor specifies how far the fin projects out from the wall that anchors it as a fraction of the window width.  Offset specifies the horizontal distance from the side of the window to the fin.  Fins stretch the entire length of each exterior wall.  If overhangs are attached to the wall, then the depth (distance out from the wall) of the fins will be the same as the overhang and the fins will be spaces equally to target the projection factor.  If no overhangs are selected, then the fins depth is assumed to be 6.6 ft (2 m).  Fins are specified separately for Front, Left, Right, and Back facades.

Skylights

Skylights are specified by the Percentage of Roof Area field.  Skylights are only applied to the core zone on the top floor of the building.

Tubular Daylighting Device

Tubular daylighting devices (TDDs) are specified by the TDD Distribution which is defined as the area per TDD.  TDDs are only applied to the core zone on the top floor of the building.

Daylighting Illuminance Setpoint

The Daylighting Illuminance Setpoint field activates automatic dimming controls for electric lighting when natural daylight is sufficient.  The Daylighting Illuminance Setpoint determines the target light level at a work plane located in the center of the zone at height of 0.8 m (2.6 ft) above the floor.  The units are in Lux. To turn off the automatic daylighting controls, set the Daylighting Illuminance Setpoint to zero.

Control Type

Daylighting controls can be setup for continuous or stepped.  "Stepped" models banks of lights of lights than can be switched off in stages.  "Continuous" models lighting systems that dim.

HVAC System Type

Select System based on:There are two ways of describing the type of HVAC system to be included in the model.  Selecting the button for "90.1-2004 Appendix G" provides a drop down list for selecting one of the 8 system types defined in Table G3.1.1B of ANSI/ASHRAE/IESNA Standard 90.1-2004.  (Basic input mode, this is assigned automatically per Table G3.1.1A). Selecting the button "Heating/Cooling Type" provides two drop lists for selecting the type of heating and cooling systems separately.  These choices were developed from the questions in 2003 CBECS.  Note that the HVAC system models included in the input file may not exactly match the topology desired but represent thermodynamically equivalent systems or the closest system available in EnergyPlus or the file generator routines. The "90.1-2004 Appendix G" HVAC system types include the following: PTAC (System 1) PTHP (System 2) PSZ-AC (System 3) PSZ-HP (System 4) Packaged VAV w/Reheat (System 5) Packaged VAV w/PFP Boxes (System 6) VAV w/Reheat (System 7) VAV w/PFP Boxes (System 8)

Outside Air Ventilation Per Person

The Outside Air Ventilation Per Person parameter identifies the minimum outdoor air ventilation rate.  This is the intentional ventilation brought in through the HVAC system to provide good indoor air quality.  A higher value will increase the rate of outdoor ventilation.  For air systems with economizers, this represents only the minimum outdoor air rate, the rate may be increased for free cooling.  In metric units, the value entered here is in units of liters per second per person.  In I-P units, the value entered here is in units of cubic feet per minute per person.  This value is added to an outside air specified using the Per Area parameter.

Outside Air Ventilation Per Area

The Outside Air Ventilation Per Area parameter identifies the minimum outdoor air ventilation rate.  This is the intentional ventilation brought in through the HVAC system to provide good indoor air quality.  A higher value will increase the rate of outdoor ventilation.  For air systems with economizers, this represents only the minimum outdoor air rate, the rate may be increased for free cooling.  In metric units, the value entered here is in units of liters per second per squre meter of floor area.  In I-P units, the value entered here is in units of cubic feet per minute per square foot of floor area.  This value is added to an outside air specified using the Per Person parameter.

Fan Static Pressure

The Fan Static Pressure parameter identifies the nominal pressure experience by the supply air fan.  The value of this parameter depends on the air system distribution system and has a strong influence on fan energy use.  A higher value will lead to more fan energy.  In metric units, the value entered here is in units of Pascals.  In I-P units, the value entered here is in inches of water.

Total Fan Efficiency

The Total Fan Efficiency parameters identifies the efficiency with which the fan motor and blower mechanisms convert electricity into air movement.

Cooling COP

The Cooling COP parameter identifies the nominal Coefficient of Performance (COP) of the mechanical cooling device.  The value entered here is the nominal COP at the rating point and performance curves are used to modify this when operating away from the rating point.  For direct expansion (DX) systems, the COP includes the fan energy on the condenser side and typically ranges from 2.6 to 4.2.  For central, water-cooled chiller systems, the COPs typical range from 5 to 6.1 and do not include any ancillaries such as pumps, fans, or cooling towers.

Heating Efficiency

The Gas Coil Efficiency parameter identifies the efficiency with which natural gas is used to provide heating.  Duct heaters for packaged systems are typically around 80% while condensing boilers may reach 95%.

Heating COP

The Heating COP only applies to electrical driven heat pumps for heating and is the nominal Coefficient of Performance (COP) of the mechanical heating device.  The value entered here is the nominal COP at the rating point and performance curves are used to modify this when operating away from the rating point.

 

Zone/Terminal Fan Static Pressure

The Zone/Terminal Fan Static Pressure parameter identifies the nominal pressure experience by the air fans in zone equipment (e.g. fan coil units) or terminal units (e.g. PFP boxes).  The value of this parameter depends on the zonal equipment and has a strong influence on fan energy use.  A higher value will lead to more fan energy.  In metric units, the value entered here is in units of Pascals.  In I-P units, the value entered here is in inches of water.

Annual Avg. Infiltration Rate

The Annual Average Infiltration Rate parameter is used to specify how leaky the building is.  Infiltration is unintentional outdoor air exchange.  The value is entered here in units of air changes per hour.  The model generated are simplified and assume a constant rate of infiltration through out the year.

Water Use

The Water Use parameter defines the rate of consumption for service water heating (also called domestic hot water).  The water use rate can be specified using different bases including: "per hour," "per day," "per person per hour," "per person per day," "per area per hour," and "per area per day."  The temperature of the service hot water, at the point of use, can also be specified.

Storage Set Point

The Storage Set Point parameter defines the temperature at which hot water is stored in the service water heating system.

Installation Type

There are three options for installing photovoltaics.None does not simulate photovoltaics. Area Percentage parameter identifies the portion of opaque surfaces that are covered with photovoltaic power systems.  The value entered here indicates percentage of the surface area that will produce solar electric power.Installed Capacity parameter is a method to enter the total system size of the photovoltaics.

Coverage Surfaces

The Coverage Surfaces parameter indicates which surfaces will have photovoltaic panels.  The "Roof Only" option will apply photovoltaic panels to each roof surface using the area percentage indicated.  The "Roof and South Facade" option will apply photovoltaic panels to each roof surface and each south-facing surface.  If windows are also present in the surfaces, only the net area of the opaque portions are included for photovoltaics.

Area Percentage

The Area Percentage parameter identifies the portion of opaque surfaces that are covered with photovoltaic power systems.  The value entered here indicates percentage of the surface area that will produce solar electric power.

Cell Efficiency

The photovoltaic modeling here uses a very simple, fixed efficiency model for solar electric power production.  The value entered for Panel Efficiency will determine the efficiency with which incoming solar radiation is converted to direct current electrical power.

Inverter Efficiency

The balance of system modeling here uses a very simple, grid-tied configuration with a fixed, overall Inverter Efficiency for converting photovoltaic power to alternating current.  The value entered here will determine the efficiency with which direct current from the photovoltaic panels is converted to alternating current for use in the building (or export to grid).