Building Automation Systems (BAS) are used in commercial HVAC control system applications. Building automation itself is an energy management system which saves companies and building owners money by efficiently controlling air conditioning and heating comfort and process systems.
BAS is where mechanical and electrical systems and equipment are joined together such that they communicate with each other and, generally, to a computer. This computer and controllers in the BAS can be networked to the internet or serve as a stand-alone system.
Building Automation System Controllers
The BAS controllers themselves do not need a computer to process the control functions, as the controllers have their own internal processors and programming.
A multi-story building would have multiple controllers serving various air conditioning and heating equipment.
Every building is different and it is important for the engineers and controls contractor to select the proper HVAC control system and programs to control the various types of HVAC systems/equipment.
Advantages of a Building Automation System
Some of the main advantages of a good building automation system are:
- BAS allow the owner or facility manager to set up schedules of operation for the equipment and lighting systems so that energy savings can be realized when the building or spaces/zones are unoccupied.
- BAS should allow the equipment optimal start with adaptive learning. Optimal start is allowing the equipment to be brought on in a sequential manner before the building is reoccupied so that space set points can be reached before occupation. Adaptive learning allows the system to compare space temperature, outside air conditions, and equipment capabilities so that the equipment can be turned on at an appropriate time to ensure space conditions are achieved before occupation.
- Based on demand the set point for various heating and cooling sources will change. In a VAV system all the VAV boxes are served from a central air handling unit. If all the zones are at set point then the supply air temperature set point of the air handler is automatically changed to prevent cooling from occurring when it is unnecessary. When the zones heat up, the supply air temperature set point is automatically lowered to allow cooling.
- BAS should send alarms via email or SMARTphone to alert building managers and/or maintenance technicians of system failures and preventative maintenance.
- Management companies who acquire a good building automation system can have the system set up to bill tenants for energy usage.
- BAS should have the communications abilities to be integrated with other building automation control systems and TCP/IP. BACnet compatible communication protocol is preferred