What is a Building Automation System?
A Building Automation System (BAS) is a computerized, “intelligent” control system that monitors and regulates the heating, ventilation and air conditioning systems and lighting in a building. A BAS keeps the building’s climate within a specific range and collects data for documentation of equipment performance. The intent is to create an intelligent building to reduce energy and maintenance costs. The BAS at UNH uses inputs such as temperature sensors to tell the system about the conditions of the space and the equipment. Then outputs from the system control the physical equipment. The control strategies are accomplished by computer programming instead of wiring electrical relays. This allows a wide variety of sophisticated control strategies resulting in greater energy efficiency without sacrificing occupant comfort.
How does a Building Automation System save energy?
Various spaces within buildings can be centrally scheduled via the BAS instead of seperate timers in each building. The computer can estimate how long it will take to get the space comfortable each day, based on outdoor and indoor temperatures, and this allows the equipment to turn on only as early as needed to warm up or cool down the space by occupancy time.
Turning off equipment when it is not needed, matching the operation of the equipment more closely to the actual needs of the space and avoiding heating and cooling at the same time are some of the ways a BAS optimizes equipment control. Equipment problems that waste energy or effect occupant comfort and safety can also use an alarm system to alert maintenance staff of a problem.
The UNH BAS is used to implement a variety of energy conservation measures such as carbon-dioxide-controlled ventilation, variable speed pump and fan systems, the use of outdoor air instead of mechanical air conditioning for cooling and energy recovery systems that capture heating and/or cooling energy from exhaust air and transfer that energy to incoming outdoor ventilation air without any direct connection (contamination) between the exhaust and inlet air streams.
UNH is currently pilot-testing software that uses data available from a BAS and runs it through algorithms to identify any equipment problems or opportunities for control schemes with greater energy efficiency.
The first BAS panels were installed at UNH in 1980 and the system has been expanded over the years to include most of the major campus buildings. Similar types of systems also control the UNH Water Treatment Plant and the Central Power Plant.