honeybee_energy.construction.window module¶
Window Construction.
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class
honeybee_energy.construction.window.
WindowConstruction
(*args, **kwargs)[source]¶ Bases:
honeybee_energy.construction._base._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
user_data
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ToString
()¶ Overwrite .NET ToString.
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duplicate
()¶ Get a copy of this construction.
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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.
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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 }
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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 }
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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.
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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.
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in_h_simple
()¶ Get the simple indoor heat transfer coefficient according to ISO 10292.
This is used for all opaque R-factor calculations.
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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).
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out_h_simple
()¶ Get the simple outdoor heat transfer coefficient according to ISO 10292.
This is used for all opaque R-factor calculations.
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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COG_AREA
= 0.76¶
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EDGE_AREA
= 0.24¶
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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.
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property
frame
¶ Get or set a window frame for the frame material surrounding the construction.
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property
gap_count
¶ The number of gas gaps contained within the window construction.
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property
glazing_count
¶ The number of glazing materials contained within the window construction.
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property
glazing_materials
¶ The only the glazing materials contained within the window construction.
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property
has_frame
¶ Get a boolean noting whether the construction has a frame assigned to it.
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property
has_shade
¶ Get a boolean noting whether dynamic shade materials are in the construction.
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property
identifier
¶ Get or set the text string for unique construction identifier.
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property
inside_emissivity
¶ “The emissivity of the inside face of the construction.
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property
inside_solar_reflectance
¶ The solar reflectance of the inside face of the construction.
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property
inside_visible_reflectance
¶ The visible reflectance of the inside face of the construction.
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property
is_dynamic
¶ Get a boolean noting whether the construction is dynamic.
This will always be False for this class.
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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.
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property
layers
¶ A list of material identifiers in the construction (outside to inside).
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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
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property
outside_emissivity
¶ “The emissivity of the outside face of the construction.
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property
outside_solar_reflectance
¶ The solar reflectance of the outside face of the construction.
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property
outside_visible_reflectance
¶ The visible reflectance of the outside face of the construction.
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property
properties
¶ Get properties for extensions.
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property
r_factor
¶ Construction R-factor [m2-K/W] (including standard resistances for air films).
Formulas for film coefficients come from EN673 / ISO10292.
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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.
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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.
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property
solar_absorptance
¶ Get the combined solar absorptance of all window panes at normal incidence.
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property
solar_reflectance
¶ The solar reflectance of the window at normal incidence (to the exterior).
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property
solar_transmittance
¶ The solar transmittance of the window at normal incidence.
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property
thickness
¶ Thickness of the construction [m].
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property
u_factor
¶ Construction U-factor [W/m2-K] (including standard resistances for air films).
Formulas for film coefficients come from EN673 / ISO10292.
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property
u_value
¶ U-value of the construction [W/m2-K] (excluding air films).
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property
unique_materials
¶ A set of only unique material objects in the construction.
This is useful when constructions reuse material layers.
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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)
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property
visible_absorptance
¶ Get the combined visible absorptance of all window panes at normal incidence.
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property
visible_reflectance
¶ The visible reflectance of the window at normal incidence (to the exterior).
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property
visible_transmittance
¶ The visible transmittance of the window at normal incidence.