First check the CFM (cubic feet per minute it pushes) of the unit, I think U need about 1000-1500 to make a difference, in electric they cost about $100 plus install.
This one is 1000 cfm at HD for $270
Nice thing is the panels can be set to suns angle, U do not want a flat top unit.
It should face due south about 180 degrees.
this is what you don't want