Case Center Upgrade
Lighting and mechanical renovations recently took place that are expected to save the University approximately 2,000,000 kWh and 846 metric tonnes of C02 annually.
“This was an opportunity to make the entire building more energy efficient,” says Aandy Ly, Director of Energy Administration and Operations. “We’ve accomplished this through successful collaboration with Construction Project Management, and Maintenance Operations.”
To begin, all 1,000-Watt mercury vapor lamps above the Ice Rink were replaced with T5HO 8-lamp fluorescent systems, which use about 500 watts. Renova, a local lighting manufacturer, custom designed fixtures so that maintenance could be performed in the attic without the need of a lift on the ice below.
In addition to the ice rink, lighting efficiency upgrades were implemented in the additional building areas, such as administrative and coach offices, lockers, lounges, restrooms, hallways, stairwells, the swimming pool, and seating areas around the ice skating rink.
Mechanical Project Overview
Infrared ice Temperature Controls
As only the top 10th of an inch of ice is used when skating, controls are set to monitor the area regardless of whether the rink is being used for hockey or figure skating.
“Figure skaters prefer softer ice so when they land they can dig in, and hockey players prefer faster ice, which is harder and colder,” says Jerry Meade, co-founder and general manager Preferred Controlled Solutions who installed and monitors the control system. The digital control system reads the floor’s temperatures through sensors embedded in the concrete and four infrared heads above. The plant, Meade says, is set up so that the two compressors can be staged and run as needed, based on the feedback of ice surface temperature.
“We also have variable frequency drives that change the speed of a motor,” says Meade. “A motor operating at full speed uses 100 percent of its energy, and a motor operating at 80 percent of its speed operates at 50 percent of its energy.”
The Demand Control Ventilation
Most environments bring in outdoor air constantly, regardless of need or indoor conditions. This includes excess heat and humidity in the summer, and excess cold air in the winter. To avoid bringing too much outside air, an array of CO2, CO temperature and humidity sensors are used to regulate and determine the specific amount required for the system based on its demand.
“When CO2 levels from exhalation rise, dampers opened, bringing in outdoor air as needed,” says Meade. “It’s a much more efficient way to maintain CO2 levels inside of a space.”
Ice Melt Pit
If you’ve ever been to an ice rink, you’ve no doubt seen a Zamboni, the large grooming machine that returns ice to a pristine state. To do this properly, ice is shaved then must be disposed of. Older rinks have traditionally placed the ice in a designated area outside. The Case Center now harnesses the cooling energy from the shaved ice to pre-cool the condensing water before entering the cooling tower. A “snow-melt pit,” which has a large radiator covered with water powered from waste heat, warms the water so when ice refuse is placed inside can be melted and reused.
Desiccant dehumidification system
While a conventional air conditioning system freezes air to remove moisture content and then reheats it before supplying it to the space, the gas-fired desiccant dehumidification technology is a more direct and efficient method to accomplish the same task. In addition, a heat exchanger for the supply air was installed to recover waste heat from the desiccant unit.
“With this new technology, we’ve effectively increased the indoor air quality while lowering the cooling costs,” says Ly. The heat exchanger, he adds, is a great way to increase the overall mechanical system efficiency by recovering the waste heat the system itself generates.
“I would expect to see a significant drop in the electricity bill of this building in the coming months,” says Ly.
Kevin Dunn, Senior Project Manager, says, “It’s important to know that if we didn’t have these desiccant humidifiers, we’d also need additional HVAC air handling units.” This, he explains, is because you’d need two separate pieces of equipment to provide the two separate functional needs.
Also completed this summer was a High-efficiency water-cooled Brine Chiller and Variable Frequency Drives for Brine Pumps and Tower Fans.
An additional project, to be complete by the summer of 2011, includes installation of a low emissivity ceiling for the rink, which will increase ceiling reflectivity and reduce radiant heat from the roof.
“This addition will not only decrease humidity condensation on the ceiling,” says Ly, “but will further brighten up the ice rink.”