Clear answer, explained.
A BAS controls the HVAC, lighting, and sometimes process systems in a commercial building — managing setpoints, schedules, and equipment operation to balance occupant comfort with energy efficiency. In theory, a well-programmed BAS significantly reduces energy consumption compared to manually controlled systems. In practice, BAS performance degrades over time without active management.
Common BAS audit findings include: HVAC systems running at full load during unoccupied hours due to outdated scheduling; sensors that have drifted out of calibration causing equipment to over-respond to incorrect readings; economiser dampers stuck in fixed positions; and heating and cooling systems running simultaneously in shoulder seasons. These issues do not require capital investment to fix — they require reprogramming and recommissioning, which is why BAS optimisation often delivers some of the fastest-returning ECMs in a commercial energy audit.
The BAS audit is conducted alongside the full energy assessment — the interval data review identifies operating hour anomalies, and the site assessment includes a controls review that documents current setpoints, scheduling programs, and sensor accuracy. The output is a specific list of BAS optimisation actions with estimated savings for each.
What this means in practice.
- A BAS audit reviews whether HVAC controls, sensors, setpoints, and scheduling are operating correctly
- BAS performance degrades over time without active management — drift is common in C&I facilities
- Common findings include HVAC running during unoccupied hours, miscalibrated sensors, and simultaneous heating and cooling
- BAS optimisation is often the fastest-returning ECM — requiring reprogramming rather than capital investment
- Interval data anomalies during audit baseline review identify BAS issues before the site visit begins
- The BAS audit output is a specific action list with estimated savings per optimisation measure
Best-fit environments.
- Your facility has a BAS but your electricity costs remain high and you suspect the controls are not performing correctly
- You have not had your BAS reviewed since original commissioning and operations have changed
- Your interval data shows HVAC consumption patterns that do not match your operating schedule
- You are planning an HVAC capital replacement and want to confirm whether recommissioning the existing system first could defer that investment
