wouldnt work, because the effort required to run the aircon unit would more than eliminate any potential power gains
first law of energy conservation!*
as sd says, water/methanol injection into the throttle body will do a much better job (mixed 50:50), although you will need a tank and pump to do this.
i know a guy in the usa who runs enginerunup.com who might help you out in this respect
*i think, its definitely one of the laws of physics tho!
Celica GT4 ST165 Sprint Special. GT3071@2.0bar