# Lighting

![](https://459479801-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ma9N5K8lMbAhbyBVgms%2Fuploads%2Fgit-blob-e8ef284cf6a664d9c0034d54200deaaa376a63a9%2FLighting.png?alt=media)

![](https://459479801-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Ma9N5K8lMbAhbyBVgms%2Fuploads%2Fgit-blob-47fe03b243038a3072c82472d84582d7121973d7%2FLighting.png?alt=media) - [\[source code\]](https://github.com/ladybug-tools/honeybee-grasshopper-energy/blob/master/honeybee_grasshopper_energy/src/HB%20Lighting.py)

Create a Lighting object that can be used to create a ProgramType or be assigned directly to a Room.

## Inputs

* **name**

  Text to set the name for the Lighting and to be incorporated into a unique Lighting identifier. If None, a unique name will be generated.&#x20;
* **watts\_per\_area \[Required]**

  A numerical value for the lighting power density in Watts per square meter of floor area.&#x20;
* **schedule \[Required]**

  A fractional for the use of lights over the course of the year. The fractional values will get multiplied by the \_watts\_per\_area to yield a complete lighting profile.&#x20;
* **radiant\_fract**

  A number between 0 and 1 for the fraction of the total lighting load given off as long wave radiant heat.&#x20;
* **visible\_fract**

  A number between 0 and 1 for the fraction of the total lighting load given off as short wave visible light.&#x20;
* **return\_fract**

  A number between 0 and 1 for the fraction of the total lighting load that goes into the zone return air (into the zone outlet node). Default: 0.0 (representative of pendant lighting).&#x20;
* **baseline**

  An optional number for the baseline lighting power density in W/m2 of floor area. This baseline is useful to track how much better the installed lights are in comparison to a standard like ASHRAE 90.1. If set to None, it will default to 11.84029 W/m2, which is that ASHRAE 90.1-2004 baseline for an office.&#x20;

## Outputs

* **lighting**

  A Lighting object that can be used to create a ProgramType or be assigned directly to a Room.&#x20;