On non-Inverter ACs, I only need to use the power input (e.g. 800W) to calculate my energy cost for a 12-hour usage. (800*12/1000 = 9.6kW-hr)
On Inverter ACs though, I know they don’t operate at 100% all the time, and most of the time the only information I get is their cooling capacity (e.g. 1hp ≈ 746W) and their EER (e.g. 12.2 kJ/hW).
How do I use these to get a rough estimate of the energy cost?
It gets even more difficult with inverters… they’re unquestionably more efficient as they don’t run balls to the wall all the time, but without taking actual readings and logging them the math is basically impossible.
I’d say it’s pretty damn difficult for both. The VFD speed is dependent on the gradient, just like the duty cycle of a conventional AC is.