Research Project Summary Information
A Novel Optical Lens for Use in Energy Saving Light(ST7513-1)
Fresnel Optics, Inc.
Motion sensors are used as part of a lighting system to automatically deactivate lights in rooms that are unoccupied. The purpose is to reduce energy usage. One particular type of motion sensor, a ceiling mount sensor, is extremely useful in large offices. The ceiling mount sensor is installed on the ceiling and can see over the cubicle to detect workers within the office. Currently, these sensors are underutilized, resulting in higher than required energy usage in many offices. They are underutilized because the existing sensors tend to deactivate the lights when people are still in the cubicle. This is a large nuisance for the end user, and they tend to either deactivate the sensor or not install them in the first place.
Fresnel Optics proposed to develop a novel Fresnel lens for use in the typical ceiling mounted motion sensor. The new optics would feature a large number of detection zones, 92 microlenses versus the current state of the art domed sensors with a maximum of 54 microlenses, higher sensitivity and a symmetric detection pattern.
People do not occupy spaces for a large percentage of time, and are not diligent about controlling the lighting in their spaces both during the workday, and after hours and weekends. The majority of this energy waste occurs during the weekdays, not during the weeknights or over the weekends. This pattern of energy waste is particularly suited to control by occupancy sensors, which not only prevent runaway operation after typical business hours, but also capture savings during the business day.
In commercial office buildings the energy use associated with lighting is typically between 20 to 30% of the buildings electrical load. The use of occupancy sensors in a large commercial office space is estimated to reduce the lighting energy use by 15 to 30% by automatically deactivating lights in an area that is unoccupied.
The expected energy savings per installed unit is estimated at $300 per year. The expected back period for install a motion sensor is about one year. With an expected installation of 6,000 units per year in New York State an annually saving of $1.8 million is estimated.
Reflexite Display Optics successfully developed and commercialized both a high (Model HC-22)) and medium density (MC-22) Passive infrared (PIR) lens for ceiling mount motion sensors. The lens provided uniform sensitivity, and a symmetrical 40 ft diameter detection pattern on the floor. The lens can be used as a (swap-in) replacement where increased sensitivity and reduced false alarms are desired.
Fresnel Optics, Inc.
1300 Mount Read Blvd
Rochester, NY 14606
NYSERDA Contact Information
Joseph C Borowiec
R&D - Buildings Research