The BTU rating of an air conditioner is NOT, a measure of how much electricity it consumes. It refers to the theoretical maximum cooling output of the unit. It's really just a means to quantify how much cooling capacity it can handle. In the housing industry, certain ratings of BTU's are good for rooms of a certain square footage. A 9k BTU would probably cool a 250sq foot room in a house. To the best of my knowledge, a 9k BTU air conditioner draws 10 amps at 110VAC or 5 amps at 220VAC. Bringing it in at about 1000 watts when running.
However the A/C doesn't always run. It only runs when the temperature gets hot enough to require it to run. So while it may be capable of removing more heat, it will run less often than a water chiller. It's unfortunately not as simple as comparing watts to watts
