Randall,

In your case the scrubber/fan combo is slowing down the air flow and increasing the temps in the process. Either a more powerful fan is in order to draw more air through the filter -or- reconfigure your exhaust fan the way you had it previously and make a stand alone scrubber that intakes and exhaust the air within your grow box placing it as high as possible so as to scrub the smell awy before it's removed by the "now stand alone' reconfigured exhaust fan. Either way should bring down the temps.