Green Technology | Feature
Smart and Smarter
Advances in automated energy-management systems are producing big cuts in heating, ventilation, and A/C costs.
- By Jennifer Grayson
Dennis Coe can laugh about it now. At the time, however, the superintendent of Henry County Schools (AL) wasn't quite so amused by the wattage-wasting antics of his students and staff. He was working overtime, he says, "just to keep the lights of the school on."
Faced with drastic cuts to his utility budget, Coe had resorted to somewhat draconian measures to save energy and cut costs, including putting lockboxes on the thermostats so that teachers and students couldn't control the temperature. But the utility bill kept creeping up.
The superintendent decided to start investigating. What he uncovered was a surprising bit of mischief. "I actually had one situation in a gym where kids, unbeknownst to the teacher, had pried the lockbox to the thermostat open so they could take it off, adjust the thermostat, and put it back on before the teacher could find out," he says with a chuckle.
The problem wasn't only limited to sweaty students looking to cool down during gym class: Coe found that in the off-hours and over summer break, contracted workers were coming in and bumping the thermostat down to 60 degrees or below to keep it cool while rewaxing the floors and performing other maintenance. "The bills were just astronomical," he says.
So Coe decided enough was enough. Last year, he contracted with energy management solutions provider Schneider Electric to install a "smart" system that automates heating, ventilation, and air conditioning (HVAC) for all five of the Henry County schools--taking control, quite literally, out of everyone's hands.
Except his own. The new IP-networked system, which was completed in February, ties all the thermostats in the district via cabling to a central computer housed in--none other than--the superintendent's office. From there, Coe and his staff can tailor temperatures to a school's schedule, turning the A/C on in the gymnasium for a basketball game one day and a beauty pageant in the auditorium the next. The system will ensure that HVAC equipment is turned off when the building is unoccupied and that the temperature never dips below a certain set point.
No one has to be uncomfortable, of course; classrooms are set at 74 degrees for cooling and 68 degrees for heat, but teachers are given a 3-degree variance so they can adjust the temperature if students are complaining. The days of 60-degree cleaning sessions, however, are a thing of the past.
All in all, the system is expected to save the district about $90,000 a year and slash energy consumption by 20 percent--sizable savings for a small, rural school system with roughly 2,900 students. And the savings will be achieved all while enrollment and technology demands increase in the years to come.
Energy management systems are nothing new, of course; for example, Texas' Corpus Christi Independent School District automated its HVAC and lighting over 10 years ago as a way to keep ballooning electricity costs in check. With the district's 4,000 classrooms, close to 40,000 students, and 20,000 computers, behavior modification alone wasn't going to make a dent in its $11 million-a-year electrical budget.
What is new, however, is how sophisticated these systems have become. In Corpus Christi, setting the air conditioners to turn off at the end of the day is just a start; recent modifications to its air distribution system allow district buildings to "adapt" to changing conditions, including humidity levels. By running the air conditioner longer--but at a lower air volume--the equipment doesn't work any harder than it has to; the school can dehumidify the air without freezing out occupants. That's crucial for a high-humidity, high-heat environment like Corpus Christi, where year-round air conditioning costs can add up quickly.
The system is also able to adjust to the number of occupants in a room. "It's just not economically feasible to leave on an air conditioner that runs $235 an hour for one person," says Scott Kucera, energy and facilities coordinator for the district.
His district has realized a $1 million-a-year payoff from its customized Schneider system, whose four-phase implementation over the past decade has also included a districtwide lighting retrofit, a computer system overhaul, and motion sensors--the installation of which will be completed this summer.
At The Hotchkiss School, a private institution founded in 1891 in Lakeville, CT, a newly installed Honeywell energy-information application works with existing building controls to analyze energy consumption in real time--allowing staff to make sure its historic buildings run as efficiently as its modern ones.
Facility managers can look at weather reports, even market conditions, to understand usage patterns and tweak the system accordingly. The system also automatically cuts energy use during periods of high demand--such as modifying temperature set points or cycling chillers on and off--helping Hotchkiss avoid higher peak-period utility costs. All told, the school has realized a return on investment of 153 percent on its energy-efficiency projects in the past three years.
These smart systems also bear the important reward of time saved. In Corpus Christi, Kucera and his meager staff of two (one assistant, one secretary) are tasked with overseeing the energy management of 60 campuses. "If a teacher calls and says, 'It's hot in here,' [now] we can look at the temperature of a room and say, 'No, it isn't' or 'Yes, it is,'" Kucera says. "And we can actually diagnose the system. Before our mechanic even leaves, he knows where to go and what's broken."
These diagnostic features will no doubt be saving Henry County man-hours, too, since before the new system went in a teacher had to call someone in maintenance "just to adjust the temperature in the room," says Coe.
And at Hotchkiss, the ability to monitor systems remotely helped avert potential disaster when a winter warm spell triggered a heat pump malfunction in the boiler plant, causing a safety pressure release valve to blow off and antifreeze to spill into the room. Alarms on the smart system immediately notified maintenance technicians, who were then able to use the system to write an emergency work-around and restart the pump.
Finding the Funds
The snag, of course, is that while districts are saving loads of money, many can't afford to make these implementations to begin with. "Of course, it's a bit cliché to say that school districts are tight on money," a Schneider Electric spokesperson says. "But now more than any time before in their history, districts are challenged to make sure that every dollar they get is funneled into the classroom."
In Henry County, for instance, where money for school utilities comes from local taxes, not the state, high unemployment rates and shrinking tax revenues left Coe wondering how he would modernize his facility.
Enter the performance contract, which allowed the district to completely fund its smart system with the money saved in energy each year. What's more, Henry County's annual $90,000 savings is guaranteed, as long as the school is implementing and following Schneider's energy plan. "We couldn't see any negatives to it," says Coe. "When the savings are guaranteed, when you're able to take those funds that are saved and invest them back into your building to make it more energy-efficient, really with no extra cost--that was a no-brainer."
Once the project is paid off, schools can choose to invest those extra funds as they see fit, either directing them toward more equipment or diverting them to other projects. Corpus Christi paid off its performance contract several years ago; now it's looking a using its annual $1 million savings for other energy-efficiency efforts, like retrofitting its older schools to achieve LEED certification.
With the money saved in Henry County, Coe may one day be able to take a more serious look at his district's energy-efficiency wish list, which includes a water management plan complete with flushless urinals.
And maybe soon, Coe will be able to count on those wattage-wasting staff and students for energy-saving aid. In Corpus Christi, Kucera has seen the folks in his district grow smarter about conservation now that they've seen the smart system in action. Whereas he used to have a hard time convincing teachers that they couldn't work in the classroom all weekend long with the A/C running, he now receives daily suggestions as to how the district can save even more money.
"It's funny," Kucera says. "Once you get people changed from wasting energy to saving it, they really jump on board."