How is trend data analysis used to verify system performance over time?

• A. Track weather patterns.
• B. Detect drifts, validate sustained performance, inform adjustments and maintenance planning.
• C. Compute project ROI.
• D. Assess building occupancy.

Answer: (B)

Trend data analysis focuses on how a system’s performance metrics evolve over time. By collecting continuous data from meters, sensors, and controls and comparing current results to established baselines and expected ranges, you can spot drift or degradation that might not be obvious from a single snapshot. This approach helps you verify that performance remains within targets across different operating conditions and seasons, not just at the start of a project.

When you detect a drift—for example, increasing energy use for the same cooling load or slower control responses—you can investigate and decide what to adjust, recalibrate, or repair. That makes it possible to plan maintenance before failures occur and to tune controls or components so performance returns to the desired level. Trend data analysis thus directly supports sustaining performance, identifying when adjustments or maintenance are needed, and guiding proactive maintenance planning.

It’s not about tracking weather patterns, calculating ROI, or simply assessing occupancy. Those activities serve different purposes and don’t provide the ongoing verification of system performance over time that trend analysis offers.