Case Studies
Washoe County School District
The Challenge
The Solution
This project included retrofits at 87 District Buildings, including the following Energy Conservation Measures (ECMs): Lighting Retrofit, Steam Trap Retrofit, DDC Installation, Water Conservation Measures, VendingMiser Installation, Trash Compactor Installation, Boiler Replacement, Burner Replacement, Rooftop HVAC Unit Replacement, VFD Installation, Ventilation Improvement.
Lighting Retrofits: Replacement/Retrofit of lighting systems at a total of eighty schools and four other District buildings. Included conversion of T-12/Magnetic Ballasts to newer T-8/Electronic Ballast Technology, conversion of incandescent lamps to compact fluorescent lamps, installation of LED exit signs, all leading to a vast improvement in the lighting systems at these buildings while significantly reducing electrical demand and usage.
Steam Trap Retrofit: Older inefficient mechanical bucket traps at five schools were replaced with new fixed orifice traps, known as “The Steamguard System”, that have no moving parts, and thus are not subject to the failure problems associated with the old steam traps. Without those failures the steam losses associated those failures are eliminated, resulting in a reduction of fuel input into the boiler.
DDC Installation: Direct Digital Controls were added at two schools to control equipment that either had no control or was poorly controlled. This installation resulted in a reduction in electricity and natural gas usage. In addition, as part of other equipment replacement projects described below, DDC was either added or upgraded.
Water Conservation Measures: At nine schools, water conservation devices for the reduction of domestic water usage were installed. The devices installed included, new flush valves on water closets and urinals, sink aerators and push button faucets, and time clocks on automatic urinal flush valves.
VendingMiser Installation: On 168 refrigerated vending machines located throughout the District the VendingMiser control device was installed, which shuts the machines off during periods of unoccupied time through the use of a wall mounted occupancy sensor, which significantly reduces the electrical usage by the machines.
Trash Compactor Installation: At 16 schools, roll-off trash compactors were installed, which allows for less frequent pickups and reduction in cost associated with trash service.
Boiler Replacement: At four schools, old in-efficient boilers, three of which utilized fuel oil as their source, were replaced with new, efficient, natural gas burning boilers. In addition, the underground fuel oil storage tanks at the applicable sites were removed and the area restored.
Burner Replacement: At two schools, old in-efficient burners, which utilized fuel oil as their source, were replaced with new, efficient, natural gas or combo gas/oil burners.
Rooftop HVAC Unit Replacement: At four schools, old in-efficient rooftop packaged HVAC equipment was replaced with new, high-efficiency HVAC units, resulting in a reduction of electrical and natural gas usage.
VFD Installation: At one school, Variable Frequency Drives (VFDs) were installed on several air handlers that had utilized inlet guide vanes or discharge dampers to vary the flow in Variable Air Volume (VAV) systems. The VFDs provide a more efficient varying of the air, which results in reduced electrical usage.
Ventilation Improvement: At four schools where air conditioning had been added in the last ten years, which provided the ventilation for the classrooms, the systems could not be used in the winter time because the existing heating system (utilizing wall mounted unit ventilators) could not keep up with heating such a large volume of cold outside air. Through installation of a heat exchanger at each site, heat from the boiler heating system can be put into the water circulation system going to the ventilation air handlers. Thus, the air can be tempered so that ventilation can be provided to the classrooms in the wintertime.
Impact
This project saves over $838,430 annually in energy costs.
