Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
It's important to point out that there are two schedules that work together for lighting:
Lighting objects that determines the fractional use of electricity for lights. This fractional schedule assumes that there are no daylighting controls.Daylighting:Controls object that determines when the daylighting controls is available to turn off or reduce the electric lighting, overriding the lighting operation schedule (input parameter above). This is availability -- the daylighting controls won't override normal operation all the time, just if enough daylight illuminance reaches the daylight sensor's position.So, if you don't need electric lighting after 6pm, that would be reflected in the lighting operation schedule -- schedule values of 0 after 6pm. This can be edited in the Schedules tab (second from the top) in the OpenStudio application.
You can read the OpenStudio Plugin for SketchUp Guide section on adding new daylighting controls for more information. It's common practice to keep the availability schedule of daylighting controls on always (constant value of 1) EXCEPT for design days, since removing daylighting controls yields higher heating/cooling capacities and helps avoid unmet heating/cooling hours during annual simulations.
| | 2 | No.2 Revision |
It's important to point out that there are two schedules that work together for lighting:
Lighting objects that determines the fractional use of electricity for lights. This fractional schedule assumes that there are no daylighting controls.Daylighting:Controls object that determines when the daylighting controls is available to turn off or reduce the electric lighting, overriding the lighting operation schedule (input parameter above). This is availability -- the daylighting controls won't override normal operation all the time, just if enough daylight illuminance reaches the daylight sensor's position.So, if you don't need electric lighting after 6pm, that would be reflected in the lighting operation schedule -- schedule values of 0 after 6pm. This can be edited in the Schedules tab (second from the top) in the OpenStudio application.
You can read the OpenStudio Plugin for SketchUp Guide section on adding new daylighting controls for more information. It's common practice to keep the From following this guide in my own testing, the daylighting controls availability schedule input is not exposed in the OpenStudio application or SketchUp plugin. If the space containing a daylight sensor (aka reference point) is assigned to a thermal zone, and the thermal zone has a primary daylight controls, then this is what the EnergyPlus Daylighting:Controls object looks like.
Daylighting:Controls,
Thermal Zone 1 DaylightingControls, !- Name
Thermal Zone 1, !- Zone Name
, !- Daylighting Method
, !- Availability Schedule Name
Continuous, !- Lighting Control Type
, !- Minimum Input Power Fraction for Cont ...
, !- Minimum Light Output Fraction for Cont ...
, !- Number of daylighting controls on always Stepped Control Steps
, !- Probability Lighting will be Reset When ...
Daylighting Control 1, !- Glare Calculation Daylighting Ref ...
0, !- Glare Calculation Azimuth Angle of View ...
, !- Maximum Allowable Discomfort Glare Index
, !- DElight Gridding Resolution {m2}
Daylighting Control 1, !- Daylighting Reference Point Name 1
1, !- Fraction of Zone Controlled by Reference ...
500; !- Illuminance Setpoint at Reference Point ...
Note that the availability schedule name input is blank, which default to "always on" (constant value of 1) EXCEPT 1). This is common practice for annual simulations, but design days, since removing daylighting days usually have daylight controls yields turned off to yield higher heating/cooling capacities and helps avoid unmet heating/cooling hours during annual simulations.
