Daylight Sensors
Daylight sensors (photosensors) measure available natural light and automatically dim or switch electric lighting to maintain a target level — saving energy and helping meet energy codes. They are central to daylight-harvesting designs near windows and skylights. Rock Lighting & Electric stocks daylight sensors from Wattstopper, Lutron, and more. Our Daylight...
Lighting Controls
Smart Controls
Wall Plates and Accessories
Fixture Controls
Cylinders
Daylight and Occupancy Sensors
Frequently Asked Questions
What is a daylight sensor?
A daylight sensor (photosensor) measures the amount of natural light in a space and signals the lighting controls to dim or switch electric lights accordingly. This daylight harvesting keeps light levels steady while cutting energy use when daylight is plentiful.
What is the difference between a daylight sensor and a photocell?
Both respond to light, but a daylight (indoor) sensor typically dims interior lighting to maintain a setpoint for daylight harvesting, while a photocell (often outdoor) switches lighting on at dusk and off at dawn. Some products combine functions.
Are daylight controls required by code?
In many commercial spaces, yes. Energy codes such as California's Title 24 require automatic daylighting controls near windows and under skylights in qualifying areas. Exact thresholds vary by code cycle, so confirm with your local authority having jurisdiction.
How do daylight sensors save energy?
By continuously matching electric light output to available daylight, the system uses only the power needed to hit the target level. Near windows and skylights this can sharply reduce lighting energy during daylight hours.