I used to have 3 conventional split a/c's, two of them running from 8pm till about 2 am. Electricity cost between 8 ad 12k. When I moved I bought to inverter split a/c's. They make no noise, no annoying breeze and my bill went down to 2500 pesos (ok including the solar water heater). In these months we are using the airco a little more and we are up to double that (including having a new maid that still needs to be trained in not wasting energy). I changed all halogen lights for LED and bulbs for low consumption bulbs, and ofcourse train everyone in the house to not leave lights, A/C, etc on when leaving a room.