Tight control of two main facets of lights – the type and how they are controlled – can lead to great savings for enterprises.
Of course, the benefits of a move to LEDs is well documented. It is perhaps the greatest combination of ease of change and percentage of gain available to building management in energy savings initiatives.
A related area in which significant gains can be realized is lighting controls and sensors. It is a category doesn’t always get as much attention as the more dramatic step of changing lighting technology. However, there is a lot to be gained, according to Michael Crane, a Senior Product Manager for Hubbell Control Solutions.
Many energy management practitioners may not be aware that there actually are classes of sensor control. An occupancy sensor determines when a person enters and leaves a room and turns the light on and off accordingly. The next level up is a vacancy sensor. This doesn’t turn the light on, but does sense a person’s presence and, when it detects that he or she has left, switches off a light if it had been manually turned on. The idea, Crane said, is that in some cases – such as a cleaning crew member popping into a room to empty an office trash basket at night – there is no need for the light to be switched on and doing so wastes energy.
The use of lighting controls can be limited by fixtures that are not accessible. This is a major challenge. “You have areas where it is difficult to retrofit or put in new controls,” Crane said. “If you have offices with hard ceilings that contractors can’t rewire, it is hard to add controls.”
The difficulties of reaching fixtures are multiplied when the devices are outside and high up on poles, such as in parking lots. Digging trenches to reach the poles essentially is a non-starter, of course.
This is where wireless technology is particularly useful. A vital first decision building and energy managers must make is to determine which wireless protocol is best for their implementation needs. Three of the most common options are ZigBee (IEEE 802.15.4), EnOcean and the Subnetwork Access Protocol (SNAP). In general, the goal is to find an approach that is low power (indeed, EnOcean harvests power from the environment) and offers self-healing characteristics, generally through mesh networks that don’t have a single point of failure.
Crane offered several things to consider when shopping for wireless lighting platforms and during the deployment phase. These issues are especially important when the lights are outdoors and spread over a wide area.
- Installation challenges: Some systems may not be appropriate for particular use cases because they can’t easily be deployed. Building and energy managers should be certain that what they buy fits their use case.
- User interface: Can the system be accessed via a Web browser? Is it a smartphone app? How the building and energy managers seek to use the system can determine which is to buy.
- Data collection: Does the platform report system status? Does it generate reports on the amount of electricity used? Management must determine what information they want now – and may want in the future.
- Radio coverage: Leafy trees and torrential rains can degrade radio frequency coverage. The outdoor wireless devices must be laid out with this in mind. Deployment strategies in southern Florida likely will be different than in Minnesota.
This week, Hubbell announced an update to its wiSCAPE Gateway. The gateway, according to the company, can manage dimming, scheduling and motion detection in as many as 1,000 wiSCAPE fixture modules. The gateway now is available with BACnet IP built-in support.
Crane said that there is a lot of activity on the wireless lighting control front, including the inclusion of the technology in fixtures. “What you are seeing now is a lot of niche players, a lot of smaller company that are coming out with a lot of different wireless product lines,” he said.