LBT DaylightSchedule - Workflows

1

Hi,
Started to explore the DaylightSchedule component and i have a couple of questions regarding the “correct” workflow to use it.

  1. One of the hints says:

using this component has several advantages over the “HB Apply Daylight Control” component under HB-Energy. Notably, it can account for setups with multiple illuminance sensors.

So i assume this is the way to go for a better coupling of lighting and energy. So far, so good.
2. I’m confused about the last sentence in the hint above. It can account for multiple sensors. This is because the next paragraph in the hint:

This component expects the annual daylight simulation to be run with one sensor
grid per room in the model. If the sensor grids within the annual daylight
simulation are distrbuted over the entire floor of each room, the resulting
schedules will be idealized, where light dimming has been optimized to supply
the minimum illuminance setpoint everywhere in the room. Grids with one, two,
> or more sensors can be used to model setups where fractions of each room are
> controlled by different sensors.

When i define a grid of only one sensor i get the schedule output for that sensor. But if i define 2 sensor points i still get one schedule, which is the combination of both sensors. What makes some confusion is the meaning of the last sentence about the use of 2, 3 r more sensors and the fraction control for each of them. I was expecting a schedule for each sensor. Otherwise, for the combined schedule for the room doesn’t make sense to define a fraction for each sensor.

  1. This is the part that i don’t get how to implement the schedules in the energy simulation. the HB_Lighting component has an input for schedule but not for rooms. So the question is how to assign the schedules to the rooms and beyond that, if having more than one sensor per zone, how to set the control fraction of each sensor?

  2. I need to define two models, one for daylighting and one for energy? The reason of this question is that in order to calculate the DaylightSchedule i need a building model, while to assign the schedules i’m still at the rooms definitions level.

Hope those questions make sense.
Thanks,
-A.

2

Hey @AbrahamYezioro ,

All good questions and I probably should improve some of the component descriptions. Here are some answers:

  1. Yes, you can set up much more detailed and accurate controls with the Radiance workflow.
  2. There is always only one schedule per room because this is all that HB-Energy and EnergyPlus can handle. Right now, we assume that each sensor corresponds to an equal fraction of room floor area. So the dimming values in the fractional schedule account for this. I understand the desire to change this default and I opened an issue for it. For now, hopefully this default still allows you to model the majority of cases.
  3. Here is a sample for how to use the Radiance results to determine the electric lighting:
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    daylight_into_energy.gh (78.4 KB)
  4. As you see in the sample above, yes. I realize that it might seem counter-intuitive but you can’t have the schedules until after the daylight simulation is run. So you need a new model after the Radiance simulation.
2 Likes
3

Thanks @chris,
This discussion is probably going to be, i believe, a reference for those that want to couple both Radiance and OS. So thanks again. I suggest to add this example to examples stock.

Your explanations are clear.
I wasn’t aware (shame on me) that ControlDaylighting in E+ allows only one schedule. I was convinced that it allows for 1 schedule per control point, which is what makes sense. Pity.
-A.

4

Ok, I added the file to the samples that we keep regularly updated with each release: