Patent Awarded for Practical, Ultra-Efficient Daylighting System

 Patent Awarded for Practical, Ultra-Efficient Daylighting System



Starfield Lighting Automation announces receiving a patent for a new type of ultra-efficient daylighting control. The system readily integrates with other energy measures, automatically coordinates with user and AV adjustments, is self-setting, maintenance-free, and is equally applicable for both single and multi-zone applications.

Daylighting, also known as daylight harvesting, is now an energy code requirement for both primary and secondary daylit zones. It is a conceptually simple process wherein electric light output is automatically adjusted to maintain a constant light level. The process works much like a thermostat but from its inception more than 30 years ago, the industry has struggled to overcome the practical issues of maintaining calibration, setpoint determination, interaction with other users, and multi-zone operation.

The problems start with calibration. Daylighting calibration is inherently difficult because the light sensors that drive the system are mounted on ceilings where they measure reflected light. Unfortunately, reflected light is constantly changing as room and sun conditions change, so without constant attention, calibration is quickly lost. Setpoint determination and interaction with other users are equally daunting. The standard “solution” to these first three problems has been to use high setpoints and suspend daylighting as soon as a user makes an adjustment. That solves the immediate problem, but at the expense of eliminating most of the energy savings.

The last of these issues, mutli-zone operation, is perhaps the most challenging. Modern architecture is bringing increased amounts of daylight into buildings so there is more daylight to harvest. The conventional solution has been to use an open loop light sensor with manually determined proportional dimming between daylight zones. However, if the problems with manual calibration, high setpoints, and user interaction are difficult for single zones, they are effectively impossible for multi-zones.

Starfield’s patented Adaptive Setpoint Daylighting process solves all these problems through the simple act of repurposing the mission of daylighting from saving energy to serving users. Field tests of this approach, along with companion measures like partial-on control, have documented consistent, long-term savings in occupied space of up to 71% while allowing unlimited user adjustment, interaction with AV and other systems, and elimination of both the initial and ongoing manual adjustments required by conventional daylighting.

Adaptive Setpoint Daylighting is available today as part of the IRIS Intelligent Room Integration System and as an option of LS230 combined occupancy/daylight sensors.

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