Fan load: watts against the curve

A fan's power rises with the cube of its speed, on top of a fixed draw for the electronics. The app fits that curve to your own unit's measured watts and compares the last day against it. **More watts at the same rpm means the fans are working harder** — a loading filter, a blocked intake, a worn bearing. It cannot tell you which of the three; it can tell you it is worth going to look. The baseline starts again at your last recorded filter change, because a clean filter is a different machine.

It needs a linked power meter, about half a day of metered running, and some variation in fan speed — Away, Boost or a night setback. At one constant speed the fixed and the speed-dependent part of the draw cannot be told apart, so the card names what is missing instead of fitting a flattering curve to nothing.