Smart and Smarter: Advances in Automated Energy-Management Systems Are Producing Big Cuts in Heating, Ventilation, and A/C Costs
Grayson, Jennifer, T H E Journal (Technological Horizons In Education)
DENNISCOE 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. …