Case Studies
UNLV: Student Housing Services
The Challenge
Student housing at the University of Nevada Las Vegas is provided by a semi-autonomous organization that is responsible for the operation of over 210,000 square feet of air-conditioned space in eleven buildings. The oldest building, constructed in 1966, still had the original mechanical equipment in 2000, and the system was not functioning well. The air conditioning system could operate either in the heating mode or cooling mode, which caused problems in the spring and fall when the building actually needed heating on the north side of the building and cooling on the south. Moreover, the 34-year-old air-cooled chiller system was in need of replacement. At the same time that e•three CES was evaluating the energy needs of student housing; bids were being solicited for construction of a new residence hall. The high costs of construction meant that the air conditioning system for the new building would have to be packaged through the wall units. Student housing was dismayed at that development because they knew first hand the high repair cost and short life of the equipment.
Our Solution
Ameresco was able to propose replacement of the existing air-cooled chiller in Tonopah Hall with a larger water-cooled chiller that was sized to handle both buildings’ load. By installing a cooling tower and plate and frame heat exchanger, the two buildings were also able to use tower free cooling to use the dry, cool, off-season air instead of using a chiller. Additional work included equipping the new cooling tower with a variable frequency drive and redesigning the piping and controls so that the buildings could simultaneously cool the south side and heat the north side of the buildings. The balance of the project consisted of a lighting retrofit for all eleven buildings wherein fluorescent lights were replaced with T8 lamps, reflectors, and electronic ballasts, incandescent lights replaced with compact fluorescent lamps, and exit signs equipped with Light Emitting Diode lights. Even the sizes of the trash bins at the buildings were upsized to reduce the frequency of pick-ups.
Impact
The project resulted in a much needed equipment upgrade in Tonopah Hall that provided the air conditioning for the Companion Hall and fixed a long-standing control issue. The energy savings generated meant that the project would pay for itself in ten years.
