Speed isn’t everything in the race to reduce NC State’s energy use. In fact, the latest innovation in the campus energy-saving toolbox shows that slow and steady can also win the cost-saving race.
On a campus with buildings dating from 1889 and energy-intensive labs conducting groundbreaking research, inefficiencies in heating, ventilation and air conditioning systems are bound to occur. Since 2012, NC State’s recommissioning program has saved $525,000 in annual energy costs by sleuthing out those energy inefficiencies one building at a time.
“I call our team ‘building doctors’ because we fix problems as we find them and educate occupants about how to better use their building,” says engineering technician Chris Young, a member of the four-person recommissioning team.
Adam Renzi, a facility mechanical engineer and recommissioning team leader, performs air balancing in Engineering Building I.
Through comprehensive HVAC audits and repairs, the recommissioning team identifies malfunctioning equipment, temperature control issues, systemic operational problems and opportunities for energy efficiency improvements.
“We look at the space as it’s being used and try to optimize the HVAC system so it can be used in the most efficient manner,” says George Smith, an automation engineer with the Building Maintenance and Operations unit that started the recommissioning team in 2012 as a pilot program.
It’s not uncommon for the team to work for several months in one building, discovering problems that may have existed since the building was constructed. In one research building, a systemic mechanical problem required redesign and replacement of the entire pumping system.
“Even though we spent a lot of money, it didn’t take long to get that back in energy savings,” Smith says. “Once these problems were fixed, the building performed so much better.”
Payback on recommissioning, including the associated repairs, has averaged less than 18 months with some buildings posting nearly 35 percent reductions in energy use per square foot. And even though the focus is energy savings, water savings typically are an added benefit. While recommissioning one building, a 2,000-gallon-per-day leak in a HVAC cooling tower was discovered and repaired.
“Over time, mechanical systems fail. But because we recommission, we find these problems sooner rather than later,” Smith says.
In order to maximize results, the team strategically selects from buildings that have digitally controlled HVAC systems and above-average energy use. Based on the success so far, the facilities division is looking at ways to increase commissioning team capacity to tackle more of the top priorities within the 350-building campus inventory.
“Those buildings are the biggest bang for the buck,” Smith says. “If we have two buildings with high energy use, we’ll choose the one where energy use is increasing.”
Occupants in the six recommissioned buildings thus far on campus — Leazar Hall, Withers Hall, Mary Anne Fox Teaching Lab, David Clark Labs, Partners II and Engineering Building I — also benefit from improved indoor air quality and temperature control as a result of recommissioning.