Thanks. I'll make sure to flip the fans on the bottom.
I'd run your pc for a bit before the change and record your idle temps and open and play a game and record your temps. Then change the fan direction and re-record temps and see what happened. That'll help you understand the impact. You may still need to add a fan at the back for exhaust if you don't see a practical improvement in temps. Or you might want to try flipping the top to intake, too with a fan at the rear and see how that affects it.
I have 9 fans in my case with 3 top, 3 front, and 2 bottom all as intake with 1 exhaust and a whole lot of air coming out the back as a result. This has the bsst results for me for noise and temps.