Dude you installed a window AC to cool off your 400watt cab? I think there has to be somthing wrong here, Do you have pics of how yur cab is setup, maybe your airflow is not correct, ie. two intake vents are better than one because you have air being drawn across more of the cab, ie cooling more efficiently. There must a more efficient way of cooling down your area.. cause adding 1000 watts of cooling to fix 400 watts of heating sounds way out of wack...