The maximum / highest bill that I paid in the year 2014 was Rs 14,750 for June 2014. This was for 37 days instead of 30 or 31 days. The Inverter ACs do save quite a bit in energy bills. But please keep in mind that I have built a new fully insulated home with double glazed windows and jumbolon on the roof and between the outer walls. My room temp without airconditioning never exceeds 33 degrees even when outside tempertures remain stagnant at 45 degrees. Therfore my ACs have less heat load to tackle with. If you have a room at 38 degrees to start with, your AC will have to work much harder to deal with the heat and your bill will be much higher compared to what I am paying. Just to give you an idea, in my old home, I was using a .75 ton mitsubihi standard AC and the bill I used to pay was 13 to 14000 a month during summer. So you can say that a .75 ton standard Ac and a good 1.5 ton inverter AC consume almost the same power. I hope this helps you.
