Hi! I currently have this build using the GT502 case.

I just recently got 3 more case fans. Previously it was set up like this:

I think that for some reason the temps got worse and the PC much louder. It might just be buyer's remorse but I got more fans so that they could use less RPM and be quieter, but I feel like the complete opposite has happened.

Can I change anything about this layout to optimise airflow? I was thinking of maybe switching the side panel fans to exhaust? That might starve the CPU cooler, though...

Maybe I'm just imagining things and I just need to perform exact tests to figure it out. What do you use for testing airflow effectiveness?

UPDATE:
The issue was weirder than I would've thought. The bottom 3 fans are controlled by one motherboard channel using a PWM splitter cable. The rear and side panel fans are the same - one channel for all 3. Previously I had just the rear exhaust plugged in to a single channel but now it's plugged into the splitter.

Apparently the order of the fans in the splitter is VERY important. I changed it so that the rear fan is the first in the splitter and that instantly fixed the issue. ¯\_(ツ)_/¯