Building Automation System (BAS)
CSI Division 25, Integrated Automation
The centralized software and hardware platform that monitors and controls a building's mechanical, electrical, and life-safety systems, HVAC, lighting, and sometimes access control, from a single interface, built on top of the individual controllers described by [[concept-direct-digital-control|direct digital control]] but adding the building-wide dashboard, scheduling, and trend-logging a facilities team actually uses day to day.
Why it matters
A BAS is only as good as the points and sequences programmed into it, and an owner who inherits a poorly commissioned BAS often ends up running systems manually or fighting a dashboard that doesn't actually reflect what's installed.
On a real project
A hospital's BAS lets facilities staff view and adjust every air handler's setpoint, schedule after-hours setbacks across the whole building, and receive an alarm the moment a critical space's temperature drifts out of range, all from one screen.
Who this matters most to
A MEP Engineer designs the sequences of operation the BAS executes. A Construction Technology Manager or the owner's facilities staff manages the platform once it's turned over. A Commissioning Agent verifies the BAS actually controls equipment the way the sequences describe.
Where this goes wrong
An owner takes over a newly commissioned BAS, but the trend logs and alarm thresholds were never tuned past the controls contractor's default settings. Facilities staff get flooded with hundreds of nuisance alarms in the first week, can't distinguish a real failure from noise, and end up disabling alarms altogether rather than sorting through them.