Close to 50% of Bentley's annual greenhouse gas emissions (carbon footprint) results from the electricity that we use in campus buildings. With this in mind The Office of Sustainability and Facilities Management have made energy efficiency a top priority.
Data for electrical sub-meters in each of Bentley's buildings is linked to the university's Energy Management System (EMS) which allows Facilities Management to determine how much electricity is being used in real time in each building on campus.
Energy Management System (EMS) Upgrades
Bentley currently utilizes three networked building energy management systems (EMS) via an online system that Facilities Management accesses daily. These systems include WebCTRL, Carrier Comfort Network and Metasys. Facilities Managers are able to access these systems to troubleshoot equipment failures and temperature issues, manage building schedules and adjust temperature set-points.
Through the EMS, Bentley's Energy Systems Engineer is able to set a building's schedule (similar to a programmable thermostat in your home) so that it is heated and cooled adequately when occupied and so that energy is not wasted heating and cooling areas when unoccupied. For example: the system can be set to automatically relax cooling and heating overnight in administrative buildings when employees are not in their offices and can turn up heating or cooling at 6:00am to ensure that temperatures are appropriate by the time employees show up for work in the morning.
Over the past few years, Bentley has been systematically upgrading EMS controls in order to manage the indoor environment more efficiently and reduce energy consumption throughout campus.
Facilities Management has historically upgraded lighting in one to two buildings per year, including the installation of occupancy sensors and energy-efficient ballasts and lamps. The majority of Bentley's buildings are equipped with high-efficiency lighting systems including LEDs, CFLs and/or system lighting controls. All outdoor lighting has also been upgraded to include LED and saving the university 584,000kW and $100,000 annually.
The construction of a 3,000 square foot solar thermal wall on the southern external wall of the Dana Athletic Center was completed in September 2009. The solar wall is made of perforated wall material and is installed several inches from the exterior wall of the building to create an air cavity.
The solar wall, which traps heat from the sun, is hooked up to a heating, ventilation and air conditioning (HVAC) unit. When the HVAC unit calls for outdoor air, the air is pulled through the solar wall and is heated in the process. The hot air rises up the air cavity created between the solar wall and the building's exterior wall and enters the HVAC unit. By providing the unit with pre-heated air, less energy is required to warm the air to room temperature.