| Lighting any workplace costs money, yet businesses | | | | While these sensors do not require a line of sight and |
| lose profits every day by paying to operate lights in | | | | can sense movement around corners and objects, |
| unoccupied rooms. A better solution is to install | | | | they may be prone to false triggering if placed too |
| automatic lighting controls—called occupancy | | | | close to an HVAC vent. Ultrasonic sensors are highly |
| sensors—that can switch lights on and off based on | | | | sensitive to small movements up to 25 feet. They |
| occupancy, time of day, and the room's ambient light | | | | typically offer a larger coverage area than |
| level. | | | | PIR sensors, but should not be mounted in high ceiling |
| Are occupancy sensors a smart solution for your | | | | applications (over 14 feet). |
| business? Read on to learn more about these | | | | |
| energy-saving devices and how they may be able to | | | | |
| help your business save energy and money. | | | | Dual-Technology Sensors |
| WHY INSTALL OCCUPANCY SENSOR | | | | |
| CONTROLS? | | | | Dual-technology sensors employ both PIR and |
| Lighting occupancy sensors save energy and money | | | | ultrasonic technologies for maximum coverage and |
| by detecting activity in work areas and automatically | | | | reliability with fewer false triggers. Because these |
| turning lights on when people enter a room and off | | | | sensors activate lights only when both technologies |
| when people have left. Used properly, occupancy | | | | detect movement, and because either of the two |
| sensors can be a cost-effective way to reduce the | | | | technologies is enough to hold the lights on, these |
| operating time of lighting systems, resulting in | | | | sensors significantly reduce the possibility of false on |
| outstanding energy savings. | | | | and off triggers. |
| One type of occupancy sensor is called a vacancy | | | | |
| sensor. Vacancy sensors must be manually turned on | | | | |
| by an occupant entering a space, but will automatically | | | | High-Bay Sensors |
| turn the lights off if no activity is sensed after a set | | | | |
| period of time. | | | | One of the most cost effective applications for |
| Vacancy sensors work best in smaller enclosed areas | | | | occupancy sensors is in warehouse aisles because |
| where occupants entering a room can easily access | | | | these areas are not occupied on a constant basis. For |
| the sensor. | | | | warehouses with highintensity discharge (HID) light |
| Occupancy sensors are most effective in spaces that | | | | sources, lighting can be switched to a lower level, but it |
| are frequently unoccupied, including offices, | | | | can't be turned completely off. HID light sources need |
| warehouses, storerooms, restrooms, loading docks, | | | | time to cool down and warm back up to full light |
| corridors, stairwells, office lounges and conference | | | | output. This process takes too long and is not practical |
| rooms. Open-plan office spaces, where activity level | | | | for those who need to perform tasks in the space. |
| may be high thoughout the workday, may not be good | | | | "High/low" occupancy controls can switch lighting from |
| candidates for occupancy sensors that control the | | | | full light output to approximately one-third light output |
| general lighting, but may be a good place to consider | | | | (which uses about half the power) when the area is |
| sensors that control plug-in office equipment and | | | | unoccupied. |
| lighting at workstations. | | | | When the sensor detects activity, the light level and |
| HOW OCCUPANCY SENSORS WORK | | | | power are restored to full almost immediately. |
| Occupancy sensors typically consist of a motion | | | | For even greater savings and instant on/off capability, |
| detector, electronic control, controllable switch (relay) | | | | consider replacing HID fixtures with high-bay |
| and power supply. Most units detect motion by sensing | | | | fluorescent fixtures. High-bay fluorescent fixtures use |
| heat (infrared radiation), shifts in the frequency of | | | | much less energy than HID, and can be switched on |
| reflected ultrasonic waves, or a combination of the | | | | and off as occupancy and vacancy is detected in a |
| two. When the sensor detects motion, the electronic | | | | space. High-bay sensors can be individually fixture |
| control sends a signal to the relay, which opens or | | | | mounted, or a single sensor can control a full aisle of |
| closes the power circuit, turning the lights on or off. | | | | light fixtures. Placement and delay settings are |
| | | | | important to prevent false triggering by detection of |
| | | | | activity in the main walkway that does not move into |
| | | | | the actual controlled aisle. Placement is also important |
| | | | | to make sure that the sensor can "see" any activity |
| | | | | anywhere in the aisle being controlled to prevent the |
| | | | | occupant from being left in the dark. |
| TYPES OF TECHNOLOGIES | | | | |
| | | | | |
| | | | | WILL OCCUPANCY SENSORS WORK FOR YOU? |
| Passive Infrared (PIR) Occupancy Sensors Infrared | | | | |
| sensors detect the difference in heat emitted by | | | | While occupancy sensors may reduce lighting by 50 |
| humans in motion from heat emitted by the | | | | percent or more in some circumstances, the savings |
| background space. While they are resistant to false | | | | could be much smaller, so it's important to consider a |
| triggering, they require a direct line of sight to sense | | | | wide range of issues before installing a sensor in a |
| motion. | | | | particular location. |
| The sensitivity of PIR sensors to small movements | | | | To determine how much benefit you will gain in a given |
| decreases at distances greater than 15 feet. As a | | | | application, monitor lighting use patterns and occupancy |
| result, these sensors are best suited for smaller, | | | | patterns simultaneously. From this, you can calculate |
| enclosed spaces where the sensor has a view of the | | | | the number of hours your business will save in lamp |
| activity in the room and warehouse aisles. The | | | | operation, and then determine your energy savings. |
| sensor's field of view can be adjusted and should not | | | | You can establish lighting use patterns in a number of |
| be directed toward an open door where it may pick | | | | ways—by observing and recording when the lights in |
| up people who are passing the doorway, but not | | | | different parts of your facility are left on, including after |
| entering the room. Ultrasonic Occupancy Sensors | | | | hours; by talking with custodial staff and security |
| Ultrasonic sensors emit a high-frequency signal that is | | | | personnel; and by reviewing the settings on lighting |
| undetectable by humans and animals. This signal | | | | timers. You can also use a device called a datalogger, |
| bounces off objects, surfaces and people in a space. It | | | | which counts lighting hours and logs lighting times and |
| then returns to the sensor, which interprets change in | | | | durations. A lighting professional can help you with this |
| the frequency as motion. | | | | process. |