Lighting. Another potential conflict between security and sustainability comes in the realm of lighting.
Outdoor Lighting. Buildings can gain LEED credits by decreasing nighttime light, glare, and overall light “pollution,” which is defined as light that illuminates areas beyond the property. Parking lot lights are often a cause of light pollution. However, many security officials worry that reducing light in parking lots to meet LEED guidelines could make the areas more vulnerable to crime.
At the green conference, Snider says, he found that while some security professionals expressed concern about this issue, those who had “worked on some projects said, ‘You know, we solved that problem real easily.’”
Snider does not see the outside lighting situation as one where either security or sustainability needs to be the loser. Rather, it is a question of having both the security and sustainability folks understand the project’s goals and work together to achieve everyone’s objectives.
“If the green guys have got the lighting engineer out there dimming down lighting levels and pointing them in certain directions, and then the security guy comes in and says, ‘I need [the lights] to go this way,’ and they don’t talk, then you’ve just either compromised your security or compromised your green building goal,” Snider says.
At the Pentagon, the lighting fixtures do not eliminate light pollution, says Nielsen, but they do minimize it. Rather than using conventional lighting fixtures with a globe at the top, the Pentagon uses fixtures that are hooded and facing downward. Many other LEED certified structures have taken that same approach. Judicious use of the right types of fixtures satisfies security needs while limiting light pollution, says Nielsen.
A problem with low lighting is that surveillance cameras have less light to work with. Many nighttime surveillance applications present that challenge, but where it might have been solved in the past by use of artificial light, the LEED goals will reduce that option.
Improvements in low-light camera technology have helped. Howell deals with the issue by attaching an infrared illuminator to camera lenses. Although the illuminators do not give off light to the naked eye, Howell says, they allow the camera to see things in almost “perfect light.”
Another workaround for reducing light pollution without compromising security is to segregate employee parking lots from visitor sites that are closed at night, says Peart. The lights over the visitor lot can be turned down overnight, and a motion sensor can be installed to activate the lights if someone enters that lot after dark.
It should also be noted that outdoor light pollution doesn’t just come from outside lights; it can also come from lights left on inside the building at night. Having drapes for building windows and requiring that they be closed at the end of the day can mitigate that issue.
Indoor Lighting. LEED awards credits for controlling lighting by using dimmers, having occupancy sensors tied to the lighting system, or by other means. Motion sensors and lighting controls can also be hooked into the main HVAC control system so that when the building occupants have all gone home, the sensor alerts the system to lower the air conditioning or heating power as well as the lights.
Companies that are known for their security systems are trying to reach out to the green market to help achieve some of the objectives. Reston, Virginia-based ObjectVideo, Inc. has exhibited its occupancy sensors to green designers as a way to gauge its potential in that market.
The sensors use video technology that can identify when there are people in rooms and to count how many. While the impetus for developing the technology has been security, it could be used to tell the building to adjust light and climate control for environmental purposes.
“This has created a whole new wave of opportunities for us,” says ObjectVideo’s Global Marketing Director Ed Troha. However, he adds that most buildings don’t yet have building management systems capable of reading such occupancy sensor data.
Howell sometimes uses an occupancy sensor to tell lights when to turn on and off; he also sometimes uses an infrared illuminator for inside cameras, as he does outside, to allow the camera to work even with little or no light. Some green buildings don’t use either method; they simply turn out the lights at night. But that could create a security vulnerability, Howell says, if someone enters the facility after hours without authorization. If lights are triggered in addition to alarms, that’s best.