# Blind Material

![](https://459479801-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ma9N5K8lMbAhbyBVgms%2Fuploads%2Fgit-blob-55168a1c3f0c066795936111f18f2d9012fb8ecc%2FBlind_Material.png?alt=media)

![](https://459479801-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ma9N5K8lMbAhbyBVgms%2Fuploads%2Fgit-blob-46c22e5eb80eadde89e31c327040fd60bcfffc85%2FBlind_Material.png?alt=media) - [\[source code\]](https://github.com/ladybug-tools/honeybee-grasshopper-energy/blob/master/honeybee_grasshopper_energy/src/HB%20Blind%20Material.py)

Create a material for a blind layer in a window construction. This material can be plugged into the "HB Window Construction" component.

Window blind properties consist of flat, equally-spaced slats.

### Inputs

* **name**

Text to set the name for the material and to be incorporated into a unique material identifier.

* **vertical**

Set to "True" to have the blinds be vertically-oriented and set to "False" to have them be horizontally-oriented. (Default: False for horizontal).

* **slat\_width**

The width of slat measured from edge to edge \[m]. (Default: 0.025 m).

* **slat\_separation**

The distance between each of the slats \[m]. (Default: 0.01875 m).

* **slat\_thickness**

A number between 0 and 0.1 for the thickness of the slat in meters. (Default: 0.001 m).

* **slat\_angle**

A number between 0 and 180 for the angle between the slats and the glazing normal in degrees. 90 signifies slats that are perpendicular to the glass. (Default: 45).

* **conductivity**

Number for the thermal conductivity of the blind material \[W/m-K]. (Default: 221, typical of aluminum blinds).

* **transmittance**

Number between 0 and 1 for the transmittance of solar radiation and visible light through the blind material. (Default: 0).

* **reflectance**

Number between 0 and 1 for the reflectance of solar radiation and visible light off of the blind material. (Default: 0.5, which is typical of a painted white blind).

* **t\_infrared**

Long-wave hemispherical transmittance of the blind material. (Default: 0).

* **emissivity**

Number between 0 and 1 for the infrared hemispherical emissivity of the blind material. (Default: 0.9, which is typical of most painted blinds).

* **dist\_to\_glass**

A number between 0.001 and 1.0 for the distance between the blind edge and neighboring glass layers \[m]. (Default: 0.05 m).

* **open\_mult**

Factor between 0 and 1 that is multiplied by the area at the top, bottom and sides of the blind for air flow calculations. (Default: 0.5).

### Outputs

* **mat**

A material for a blind layer in a window construction that can be assigned to a Honeybee Window construction.