Exhaust on your side panel is probably the worse place to position it. Thats because its the best position for intake. Same with your cpu fan. If your cpu fan was to act as an exhaust, your system would be alot hotter. Air cooling differs then liquid cooler. Liquid cooling, you setup, and thats really it. But air cooling, acts different. If your fans arent arranged currectly, it simply wont make a differience, or the worse possible situation, it can result in a negitive affect.
I suggest having the dual side panel fans as intake. Then the rear fan as exhaust. You never want more intake, always slightly more exhaust. So in order to counter that, make sure your dual intakes have less CFM. While your exhaust is a high out-put fan. MODing exhaust on the top of your case would help alot. That enables you to put high out-put fans as intake also.