honeybee_energy.construction.window module

Window Construction.

class honeybee_energy.construction.window.WindowConstruction(identifier, materials, frame=None)[source]

Bases: _ConstructionBase

Window energy construction.

Parameters

  • identifier – Text string for a unique Construction ID. Must be < 100 characters and not contain any EnergyPlus special characters. This will be used to identify the object across a model and in the exported IDF.

  • materials – List of materials in the construction (from outside to inside). The first and last layer must be a glazing layer. Adjacent glass layers be separated by one and only one gas layer. When using a Simple Glazing System material, it must be the only material.

  • frame – An optional window frame material to denote the frame that surrounds the window construction. (Default: None).

Properties:

  • identifier

  • display_name

  • materials

  • layers

  • unique_materials

  • frame

  • r_value

  • u_value

  • u_factor

  • r_factor

  • is_symmetric

  • has_frame

  • has_shade

  • is_dynamic

  • inside_emissivity

  • outside_emissivity

  • solar_transmittance

  • solar_reflectance

  • solar_absorptance

  • visible_transmittance

  • visible_reflectance

  • visible_absorptance

  • shgc

  • thickness

  • glazing_count

  • gap_count

  • glazing_materials

  • inside_material

  • outside_material

  • user_data

  • properties

ToString()

Overwrite .NET ToString.

duplicate()

Get a copy of this construction.

static extract_all_from_idf_file(idf_file)[source]

Get all WindowConstruction objects in an EnergyPlus IDF file.

Parameters

idf_file – A path to an IDF file containing objects for window constructions and corresponding materials. For example, the IDF Report output by LBNL WINDOW.

Returns

A tuple with two elements

  • constructions: A list of all WindowConstruction objects in the IDF file as honeybee_energy WindowConstruction objects.

  • materials: A list of all window materials in the IDF file as honeybee_energy Material objects.

classmethod from_dict(data)[source]

Create a WindowConstruction from a dictionary.

Note that the dictionary must be a non-abridged version for this classmethod to work.

Parameters

data – A python dictionary in the following format

{
"type": 'WindowConstruction',
"identifier": 'Generic Double Pane U-250 SHGC-035',
"display_name": 'Double Pane Window',
"materials": [],  # list of material objects (from outside to inside)
"frame": {}  # an optional frame object for the construction
}
classmethod from_dict_abridged(data, materials)[source]

Create a WindowConstruction from an abridged dictionary.

Parameters

  • data – An WindowConstructionAbridged dictionary with the format below.

  • materials – A dictionary with identifiers of materials as keys and Python material objects as values.

{
"type": 'WindowConstructionAbridged',
"identifier": 'Generic Double Pane U-250 SHGC-035',
"display_name": 'Double Pane Window',
"materials": [],  # list of material identifiers (from outside to inside)
"frame": 'AL with thermal break'  # identifier of frame material
}
classmethod from_idf(idf_string, ep_mat_strings)[source]

Create an WindowConstruction from an EnergyPlus text string.

Parameters

  • idf_string – A text string fully describing an EnergyPlus construction.

  • ep_mat_strings – A list of text strings for each of the materials in the construction.

classmethod from_simple_parameters(identifier, u_factor, shgc, vt=0.6)[source]

Create a WindowConstruction from a specification of simple parameters.

The result will have a single EnergyWindowMaterialSimpleGlazSys layer that is derived from the input parameters.

Parameters

  • identifier – Text string for a unique construction ID. Must be <90 characters and not contain any EnergyPlus special characters. This will be used to identify the object across a model and in the exported IDF.

  • u_factor – A number for the U-factor of the glazing system [W/m2-K] including standard air gap resistances on either side of the system.

  • shgc – A number between 0 and 1 for the solar heat gain coefficient of the glazing system. This includes both directly transmitted solar heat as well as solar heat that is absorbed by the glazing system and conducts towards the interior.

  • vt – A number between 0 and 1 for the visible transmittance of the glazing system. Default: 0.6.

in_h(t_kelvin=293.15, delta_t=15, height=1.0, angle=90, pressure=101325)

Get the detailed indoor heat transfer coefficient according to ISO 15099.

This is used for window U-factor calculations and all of the temperature_profile calculations.

Parameters

  • t_kelvin – The average between the indoor temperature and the interior surface temperature. Default is 293.15K (20C).

  • delta_t – The temperature difference between the indoor temperature and the interior surface temperature [C]. Default is 15C.

  • height – An optional height for the surface in meters. Default is 1.0 m, which is consistent with NFRC standards.

  • angle – An angle in degrees between 0 and 180. 0 = A horizontal surface with downward heat flow through the layer. 90 = A vertical surface 180 = A horizontal surface with upward heat flow through the layer.

  • pressure – The average pressure in Pa. Default is 101325 Pa for standard pressure at sea level.

in_h_simple()

Get the simple indoor heat transfer coefficient according to ISO 10292.

This is used for all opaque R-factor calculations.

lock()[source]

The lock() method will also lock the materials.

out_h(wind_speed=6.7, t_kelvin=273.15)

Get the detailed outdoor heat transfer coefficient according to ISO 15099.

This is used for window U-factor calculations and all of the temperature_profile calculations.

Parameters

  • wind_speed – The average outdoor wind speed [m/s]. This affects the convective heat transfer coefficient. Default is 6.7 m/s.

  • t_kelvin – The average between the outdoor temperature and the exterior surface temperature. This can affect the radiative heat transfer. Default is 273.15K (0C).

out_h_simple()

Get the simple outdoor heat transfer coefficient according to ISO 10292.

This is used for all opaque R-factor calculations.

solar_optical_properties()[source]

Get solar transmittance + reflectance, and absorptances for each glass pane.

Returns

A tuple of three values.

  • transmittance: A transmittance value through all glass panes.

  • reflectance: A reflectance value from the front of all glass panes.

  • absorptances: A list of absorptance values through each pane of glass. The values in this list correspond to the glass panes in the construction.

temperature_profile(outside_temperature=-18, inside_temperature=21, wind_speed=6.7, solar_irradiance=0, height=1.0, angle=90.0, pressure=101325)[source]

Get a list of temperatures at each material boundary across the construction.

Parameters

  • outside_temperature – The temperature on the outside of the construction [C]. (Default: -18, consistent with NFRC 100-2010).

  • inside_temperature – The temperature on the inside of the construction [C]. (Default: 21, consistent with NFRC 100-2010).

  • wind_speed – The average outdoor wind speed [m/s]. This affects outdoor convective heat transfer coefficient. (Default: 6.7 m/s).

  • solar_irradiance – An optional value for solar irradiance that is incident on the front (exterior) of the construction [W/m2]. (Default: 0 W/m2).

  • height – An optional height for the surface in meters. (Default: 1.0 m).

  • angle –

    An angle in degrees between 0 and 180.

    • 0 = A horizontal surface with the outside boundary on the top.

    • 90 = A vertical surface

    • 180 = A horizontal surface with the outside boundary on the bottom.

  • pressure – The average pressure of in Pa. (Default: 101325 Pa for standard pressure at sea level).

Returns

A tuple with two elements

  • temperatures: A list of temperature values [C]. The first value will always be the outside temperature and the second will be the exterior surface temperature. The last value will always be the inside temperature and the second to last will be the interior surface temperature.

  • r_values: A list of R-values for each of the material layers [m2-K/W]. The first value will always be the resistance of the exterior air and the last value is the resistance of the interior air. The sum of this list is the R-factor for this construction given the input parameters.

temperature_profile_frame(outside_temperature=-18, inside_temperature=21, outside_wind_speed=6.7, solar_irradiance=0, height=1.0, angle=90.0, pressure=101325)[source]

Get a list of temperatures across the frame of the construction.

Note that this method will return None if no frame is assigned to the construction.

Parameters

  • outside_temperature – The temperature on the outside of the construction [C]. (Default: -18, consistent with NFRC 100-2010).

  • inside_temperature – The temperature on the inside of the construction [C]. (Default: 21, consistent with NFRC 100-2010).

  • wind_speed – The average outdoor wind speed [m/s]. This affects outdoor convective heat transfer coefficient. (Default: 6.7 m/s).

  • solar_irradiance – An optional value for solar irradiance that is incident on the front (exterior) of the construction [W/m2]. (Default: 0 W/m2).

  • height – An optional height for the surface in meters. (Default: 1.0 m).

  • angle –

    An angle in degrees between 0 and 180.

    • 0 = A horizontal surface with the outside boundary on the bottom.

    • 90 = A vertical surface

    • 180 = A horizontal surface with the outside boundary on the top.

  • pressure – The average pressure of in Pa. (Default: 101325 Pa for standard pressure at sea level).

Returns

A tuple with two elements

  • temperatures: A list of temperature values [C]. The first value will always be the outside temperature and the second will be the exterior surface temperature. The last value will always be the inside temperature and the second to last will be the interior surface temperature.

  • r_values: A list of R-values for each of the material layers [m2-K/W]. The first value will always be the resistance of the exterior air and the last value is the resistance of the interior air. The sum of this list is the R-factor for this construction given the input parameters.

to_dict(abridged=False)[source]

Window construction dictionary representation.

Parameters

abridged – Boolean to note whether the full dictionary describing the object should be returned (False) or just an abridged version (True), which only specifies the identifiers of material layers. Default: False.

to_idf()[source]

IDF string representation of construction object.

Note that this method only outputs a single string for the construction and, to write the full construction into an IDF, the construction’s unique_materials must also be written. If the construction has a frame, the frame definition must also be written.

Returns

construction_idf – Text string representation of the construction.

to_radiance_solar()[source]

Honeybee Radiance modifier with the solar transmittance.

to_radiance_visible()[source]

Honeybee Radiance modifier with the visible transmittance.

to_simple_construction()[source]

Get a version of this construction that uses a SimpleGlazSys material.

This is useful when translating to gbXML and other formats that do not support layered window constructions.

unlock()[source]

The unlock() method will also unlock the materials.

visible_optical_properties()[source]

Get visible transmittance + reflectance, and absorptances for each glass pane.

Returns

A tuple of three values.

  • transmittance: A transmittance value through all glass panes.

  • reflectance: A reflectance value from the front of all glass panes.

  • absorptances: A list of absorptance values through each pane of glass. The values in this list correspond to the glass panes in the construction.

COG_AREA = 0.76
EDGE_AREA = 0.24
property display_name

Get or set a string for the object name without any character restrictions.

If not set, this will be equal to the identifier.

property frame

Get or set a window frame for the frame material surrounding the construction.

property gap_count

The number of gas gaps contained within the window construction.

property glazing_count

The number of glazing materials contained within the window construction.

property glazing_materials

The only the glazing materials contained within the window construction.

property has_frame

Get a boolean noting whether the construction has a frame assigned to it.

property has_shade

Get a boolean noting whether dynamic shade materials are in the construction.

property identifier

Get or set the text string for unique construction identifier.

property inside_emissivity

“The emissivity of the inside face of the construction.

property inside_material

The the inside material layer of the construction.

Useful for checking that an asymmetric construction is correctly assigned.

property inside_solar_reflectance

The solar reflectance of the inside face of the construction.

property inside_visible_reflectance

The visible reflectance of the inside face of the construction.

property is_dynamic

Get a boolean noting whether the construction is dynamic.

This will always be False for this class.

property is_symmetric

Get a boolean to note whether the construction layers are symmetric.

Symmetric means that the materials in reversed order are equal to those in the current order (eg. ‘Gypsum’, ‘Air Gap’, ‘Gypsum’). This is particularly helpful for interior constructions, which need to have matching materials in reversed order between adjacent Faces.

property layers

A list of material identifiers in the construction (outside to inside).

property materials

Get or set the list of materials in the construction (outside to inside).

The following rules apply:

  • The first and last layer must be a glazing layer.

  • When using a Simple Glazing System material, it must be the only material.

  • Adjacent glass layers must be separated by one and only one gas layer

  • Shades/blinds are not allowed; WindowConstructionShade must be used

property outside_emissivity

“The emissivity of the outside face of the construction.

property outside_material

The the outside material layer of the construction.

Useful for checking that an asymmetric construction is correctly assigned.

property outside_solar_reflectance

The solar reflectance of the outside face of the construction.

property outside_visible_reflectance

The visible reflectance of the outside face of the construction.

property properties

Get properties for extensions.

property r_factor

Construction R-factor [m2-K/W] (including standard resistances for air films).

Formulas for film coefficients come from EN673 / ISO10292.

property r_value

R-value of the construction [m2-K/W] (excluding air films).

Note that shade materials are currently considered impermeable to air within the U-value calculation.

property shgc

Get the solar heat gain coefficient (SHGC) of the construction.

If this construction is not a simple glazing system, this value is computed by summing the transmitted and conducted portions of solar irradiance under the NFRC summer conditions of 32C outdoor temperature, 24C indoor temperature, and 783 W/m2 of incident solar flux.

property solar_absorptance

Get the combined solar absorptance of all window panes at normal incidence.

property solar_reflectance

The solar reflectance of the window at normal incidence (to the exterior).

property solar_transmittance

The solar transmittance of the window at normal incidence.

property thickness

Thickness of the construction [m].

property u_factor

Construction U-factor [W/m2-K] (including standard resistances for air films).

Formulas for film coefficients come from EN673 / ISO10292.

property u_value

U-value of the construction [W/m2-K] (excluding air films).

property unique_materials

A set of only unique material objects in the construction.

This is useful when constructions reuse material layers.

property user_data

Get or set an optional dictionary for additional meta data for this object.

This will be None until it has been set. All keys and values of this dictionary should be of a standard Python type to ensure correct serialization of the object to/from JSON (eg. str, float, int, list, dict)

property visible_absorptance

Get the combined visible absorptance of all window panes at normal incidence.

property visible_reflectance

The visible reflectance of the window at normal incidence (to the exterior).

property visible_transmittance

The visible transmittance of the window at normal incidence.