When buying an air conditioner, you have to compute the capacity needed for the particular area. As an actual example, when we were looking for a new air conditioning unit, the window type was offered to us which was just 0.9 HP (horse power). My wife immediately agreed because the salesman focused on the electric consumption in his sales talk. Naturally the 0.9 HP consumes less than the 1 HP unit. However, based on the computation I made, we need at least 1 HP even for a window type. The 0.9 HP may not be able to properly cool our bedroom. And I was right on that. When we had bought and installed the 1 HP, it was pretty good.