WattStopper recently announced the new LMLS-600 dual loop photosensor that provides superior automatic daylighting control for applications with skylights. Developed in cooperation with the California Lighting Technology Center (CLTC), Wal-Mart and three California utilities, the device includes two photosensors – an open loop sensor to detect daylight contribution, and a closed loop sensor to read the ambient light level – and sophisticated algorithms to simplify setup and ensure optimal performance.
The LMLS-600 is the first commercial product to combine open and closed loop daylighting control strategies to prevent unwanted lighting changes, and increase energy savings. During normal operation, the closed loop sensor provides control based on the ambient light level. However, if the device detects occupant interference, the open loop sensor takes control for the remainder of the day. Previously, daylighting control for skylit areas typically relied on open loop solutions, which can cause distracting changes to electric light levels when the sun is low in the sky. Closed loop solutions overcome this problem, but on their own tend to over dim or under dim the lights.
The new photosensor features automatic commissioning, including self-calibration and establishment of setpoints, saving time for installers and improving performance. Additionally, it recalibrates itself every night to adapt to reflectance changes in the space, such as a new furniture layout, a new retail display or lamp lumen depreciation.
The LMLS-600 can be set up for switching or dimming control, and is part of WattStopper’s Digital Lighting Management (DLM) suite of intelligent controls. Combined with DLM room controllers, it can control most lighting loads, including LEDs. Set up is ladder free, from a wireless handheld configuration tool that is also used to customize a wide variety of DLM control parameters.
Proof-of-concept demonstrations showed the dual-loop solution achieves 36% energy savings compared to the 24% achieved by the open-loop solution. This 50% increase in performance will help lighting, design and building professionals comply with new code requirements for daylighting controls and energy efficiency in commercial, retail, warehouse, and industrial applications.