On this page 3 sections
Daylight harvesting where daylight reaches the task — calibrated, not left at factory default
Daylight controls only work where daylight reaches the task. A sensor on a dark wall, or a calibration that was never done, is a complaint waiting for the first week of occupancy.
Switching the rest of the floor
A switch, a dimmer, or a panel is lighting controls.
Empty rooms
Occupancy sensors where people leave are occupancy controls.
The office layout
Open plan versus meeting rooms is office lighting.
Daylight controls: the daylit zone the code defines, and the calibration that makes it work
California Title 24 requires automatic daylighting controls in the primary and secondary daylit zones of most commercial floors with real glass or skylights. The requirement is met only when the photosensor is placed and calibrated to that zone — not left at a factory default.
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The zone, not the room
Title 24 defines the daylit zone by the window and skylight geometry. Controls are required inside that zone and are pointless outside it — which is why a sensor on a dark wall fails both the code and the occupants.
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Open-loop or closed-loop
A high open-loop sensor drives a whole zone; a closed-loop sensor reads the task it dims. The daylight pattern and the fixture layout decide which one holds its calibration.
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Commissioning is the job
Continuous or stepped dimming, the setpoint, and the fade are tuned during occupancy. An uncommissioned daylight system generates complaints in the first week of occupancy — the calibration, not the hardware, is what makes it work.
When daylight controls aren’t the right job
Dimming where daylight actually reaches the task is this job. A floor that needs switching, and a room that empties out, are different pages.
The floor needs switching, not daylight dimming
That is lighting controls.
The room empties and should go off
That is occupancy controls.
Daylight controls questions
The sensors never got calibrated.
Then they are a complaint, not a control. Daylight harvesting only works where daylight reaches the task, and only after calibration.
There is no real daylight on that wall.
Then this isn’t the right job. Switching the occupants will live with is lighting controls.
The meeting rooms also need occupancy.
Empty-room sensors are occupancy controls. Do not use a daylight sensor as a vacancy sensor.
The office layout changed.
Then start at office lighting. Daylight zones follow the glass and the desks, not the old grid.
What does the term "daylight harvesting" refer to?
Dimming or switching electric lights when daylight at the window already does the job.
Still not sure it is the right job? Call (279) 972-9272 — available 24 hours.
Serving 19 communities across the Sacramento area
Litel Electric serves businesses throughout all 19 communities in our service area — from Davis and Woodland to Roseville, Folsom, and Elk Grove.
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Tell us what is happening, or what you are planning. We read the details, tell you what else we need to know, and explain the next step before anything is scheduled.
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You send the problem or the plan, with the address if you have it.
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We reply with what it involves and what has to be seen in person.
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Nothing is scheduled, and nothing is priced, until the equipment has been looked at.
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