Building Systems and Controls
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90% of UMD’s emissions come from heating and powering our campus buildings. Reducing emissions from heating and cooling not only lowers UMD’s utility bills and carbon footprint, but also brings us closer to becoming a carbon neutral campus, as outlined in UMD’s Energy Action Plan.
Building Systems and Controls (BSAC)
Facilities Management’s BSAC team monitors the heating and cooling of buildings on campus. Even with efficient buildings and the latest green technologies, it’s no easy task maintaining a comfortable climate across the UMD campus. Air needing to be heated in some areas while cooled in others, removing moisture from the air, and bringing in fresh air are variables that are constantly monitored and adjusted by the BSAC team.
BSAC staff are critical to reducing campus emissions. Maintaining heating, ventilation, and air conditioning (HVAC) equipment is essential to their efficiency as well as continued use. Efficiency is about using less to get the same result, BSAC staff are constantly searching for new ways to make the system more efficient to save on campus utility bills.
Buildings across campus are structurally diverse and vary in their heating and ventilation controls. Facilities Management staff are working to find the best balance of supporting campus operations and energy conservation.
At a first glance, the HVAC system at UMD would seem to be contradictory. The steam and chilled water loops are run simultaneously as some areas are cooled while others require heating. These seemingly contradictory operations are necessary to keeping buildings at UMD comfortable.
Making a change in one area often creates a cascading effect, as competing subsystems need to be readjusted. This can create many local control issues, oftentimes valves and thermostats have to be manually adjusted by BSAC staff.
Turning on the air conditioning at UMD is not as easy as flipping a switch, so the process begins as early in the season as possible . Chilling towers have to be flooded and coils in the air handling systems are filled with water to prepare for the cooling season. The process takes about a week to complete. To prevent equipment damage, as well as subsequent damage to buildings, this process cannot be started until the chance of outdoor air temperatures below freezing has passed. This occasionally results in warmer than desired indoor air temperatures on unseasonably warm days.
Once the system is prepared, cool water from the chillers is pumped to the cooling coils in the air handling units which in turn cool the air supplied to the occupied spaces. To remove heat from the water cooled condensers on the chillers the water is cooled by contact with the atmosphere as the condenser water is circulated between the chillers and the cooling towers.
When BSAC staff switch their operations from the heating season to the cooling season, there is an opportunity to save energy by delaying the start up of the air conditioning chillers. BSAC staff monitor the weather and trends to estimate when it is actually necessary to start cooling campus.
During winter breaks the UMD campus shuts down all of the mechanical systems except the essential ones. All of the buildings are closed and the UMD campus reduces their utility bills and greenhouse gas emissions by going into a low-occupancy mode. Campus buildings are operated at temperatures lower than normal and with limited ventilation. This process saves systems from unnecessarily running and reduces carbon emissions as well as heating costs.
In the past over that 11 day period, Natural gas use in the campus heating plant was reduced by 2,151 million cubic feet- which translates into 113 metric tons of greenhouse gases. Monetary savings in natural gas from the campus heating plant were $14,562, a reduction of nearly 13% over the same period the previous year.
More recently over winter break, UMD was able to save 231 metric tons of greenhouse gas emissions (89 and 142 metric tons of greenhouse gases saved from electric and heating, respectively), saving 53 metric tons more than the previous break. Our goal is to continue to increasing or savings through more inclusive and thorough system shut-downs. In this way we can continue to reduce our greenhouse gas emissions and improve our community.
Building Control Technologies
In addition to equipment and software that allow for precise measurements, BSAC staff also use other means to make heating and cooling the campus more efficient.
Some classrooms and offices are now operated on occupancy sensors. While classrooms are unoccupied variable frequency fans are turned down. In the winter, this results in cooler rooms that warm as the day goes on. This small change makes a huge difference, as the fans use less energy and the steam plant needs to produce less heat.
While some HVAC adjustments have to be made manually by the BSAC staff, many adjustments can be made remotely. A centralized system allows changes to be made within moments of identification of a problem. In addition, BSAC staff also use smart phone apps that allow access to building controls, making changes possible from anywhere.
With a commitment to sustainability, Facilities Management staff are dedicated to serving the campus while minimizing energy use and utility costs. This balance can save money and reduce environmental impacts. However, sometimes indoor comfort issues are an indication of larger problems with the heating, ventilation, and air conditioning systems.
If you have concerns or experience extremely warm or cold conditions, please contact Facilities Management at x8262.