Sustainability at the University of St. Thomas
Opus Hall, Minneapolis campus
- Parabolic lighting fixtures installed with acrylic lenses reducing energy use as well as the number of fixtures needed while maintaining 70 foot candle lighting. Fixtures use F32T8 lamps which are a higher output and lower watt tube. All fixtures use electronic ballasts reducing energy use needed to start lamp. Lighting needs only 1.5-1.7 watts per square foot.
- Occupancy sensors for lighting controls in all offices & classrooms
- Classroom perimeters are equipped with continuous dim-able ballasts with photo sensing controls on the two light banks closest to windows. The lighting maintains 50 foot candles of light at the desk surface by dimming on sunny days and brightening on cloudy.
- Dual level light switching in classrooms allows instructors to use 33%-66%-100% of lights
- Windows are Low-E glazed, special tint with aluminum frames to reduce solar gain for AC in the summer and heat loss in cold months. U value is .42, shading coefficient .42, visual transmission .62.
- Rooftop water cooled DX high efficiency cooling unit installed with an efficiency rating greater than the Minnesota energy code. By installing the cooling unit on the rooftop, heat dissipation takes place outside the building and does not have to be exhausted requiring additional energy.
- VSD (variable speed drive) motors are installed on all air handling units for supply and return as well as all heating pumps. Using variable speeds for slower off peak use allows reduction of air handled by the fans, reduces the number of filters, belts, and bearings that must be replaced, reduces labor needed for maintenance, prolongs the life of the motor, and significantly reduces energy use.