Best Practices
Geothermal Heating and Cooling
In September of 2000, the York County School Division completed its first geothermal renovation at Tabb Middle School. The subsequent energy savings achieved at that site prompted similar renovations throughout the school division. Today, one third of the school buildings in the division have been converted to geothermal heating and cooling systems with more to soon follow. These renovations have reduced site energy consumption by up to 40%.
Best Practice – Geothermal Heating and Cooling
Lighting Upgrades
Beginning in 1997, the York County School Division has upgraded light fixtures in every classroom, office and hallway from T12 fluorescent to T8 fluorescent, reducing lighting costs by nearly 40%
Best Practice - Lighting Upgrades
In the past year, seven school gymnasiums received lighting upgrades from HID fixtures to more efficient high-bay T5 fixtures: Bethel Manor Elementary, Coventry Elementary, Grafton Bethel Elementary, Magruder Elementary, Mt. Vernon Elementary, Tabb Elementary and Yorktown Elementary.
- Mount Vernon Elementary School Gym - Before and After
- Yorktown Elementary School Gym - Before and After
- Bethel Manor Elementary School Cafeteria - Before and After
- Jennifer Goodwin, Assistant Principal, Tabb Elementary School
Occupancy Sensors
Most classroom, office, cafeteria and gymnasium lights in the school division are controlled by occupancy sensors which save energy by automatically turning off lights when the areas are unoccupied.
Direct Digital Building Automation System
The York County School Division uses an enhanced building automation system (BAS) that is installed in all of the division’s buildings. This BAS system incorporates a wide array of software tools to manage building and equipment operation and reduce energy consumption which include:
- Shifting the heating & air-conditioning (HVAC) systems to setback temperatures at night, weekends and holidays
- Recalculating HVAC equipment start and stop times daily based on current room temperature and outside air temperature
- Controlling the electrical demand peaks by load shedding
- Lighting control
- Logging temperatures and run times of equipment so that proper operation can be verified
Energy Recovery Units
The York County School Division uses heat wheel style energy recovery units. These units cut energy consumption by reducing the amount of energy needed to condition fresh air entering the building. Schools that utilize heat wheel style energy recovery: Tabb Middle, Tabb High, Bethel Manor, Yorktown Middle, York High, Queens Lake Middle, and Bruton High.
Best Practice - Centralized Fresh Air Make Up System
Best Practice - Energy Recovery Units
Windows
When possible, the York County School Division has upgraded windows to thermal pane double insulated windows. Examples from the recently renovated York High School’s new windows:
Energy Management Team
The York County School Division employs a three-person energy management team, each dedicated to different areas of the energy conservation program.
- The Supervisor of Resource and Security Control is a Certified Energy Manger (CEM), a certified commissioning professional, and a member of the Association of Energy Engineers. His duties include:
- Directing engineers in the design of HVAC systems, building automation systems and lighting in new construction and renovations
- Overseeing the installation and programming of the building automation system
- The Building Automation and Security Analyst
- Installs, programs and monitors the building automation system (BAS)
- Develops control strategies to achieve the most efficient operation of equipment
- The Energy Educator
- Monitors all school division utility bills and tracks consumption using Energy Star’s Portfolio Manager and Energy Cap software
- Performs regular daytime, nighttime and holiday energy audits of all buildings
- Educates school faculty and staff on good energy conservation practices
Ozone Systems
The York County School Division has installed ozone water treatment systems to treat the cooling tower water on schools which have closed circuit evaporative cooling towers. This process began several years ago when it was discovered that a water treatment system had not been specified or installed on two 300 ton evaporative cooling towers at one of the schools. After a thorough investigation the division elected to install an ozone system on these two towers rather than a standard chemical treatment system. This decision was based on the following factors:
- Due to the location of the cooling towers a standard chemical/biocide treatment system installation would require the transportation of hazardous chemicals through the interior of the high school to the boiler room. This practice could lead to a potential spill and the risk was not acceptable.
- A standard chemical/biocide treatment system installation would require that the tower water effluent resulting from blow downs to maintain proper water chemistry need to be delivered to a sanitary drain in order for it to be treated properly. Installing the necessary drainage piping would have been an additional cost.
- Water effluent from a tower treated with ozone can be discharged directly to a roof or storm drain since the water effluent does not require additional treatment to remove the ozone.
- Ozone use reduces the number of blow-down cycles required to maintain proper water conductivity thereby reducing water consumption.
- The cost of purchasing chemicals and biocides each month was eliminated.
- The cost of installation and maintenance for chemical injection pumps for the water treatment chemicals which were not required was eliminated.
Some of the environmental significant benefits of using ozone water treatment systems on the cooling towers are:
- Completely eliminated the need to discharge chemically treated water from the cooling towers for water chemistry control.
- Reduced water consumption by reducing the number of blow-down cycles required to maintain the proper water conductivity.
- Protected the children from potential harm from bacteria and hazardous chemicals.
- Prevented the formation of legionella pneumophila bacteria in the cooling towers (some of the cooling towers are located relatively close to playgrounds).
- Eliminated the need to transport hazardous chemicals through the school buildings.
- Dramatically improved the condition and appearance of the water in the cooling towers.
- Maintained or increased the efficiency of the cooling towers by eliminating the scale build-up on the tubes.
- Dramatically reduced the cost of maintenance required to keep the towers clean by eliminating the build-up of scale on the tubes and cooling tower interior surfaces.
Best Practice – Ozone Systems