Do you have a Phat PS3 that overheats? It's a common problem. I spent a lot of time in repairs and research to identify two components that significantly improve the overheating problem:
1. 19 Blade Fan
More blades than the standard fan means more air circulation
2. APS-231 Power Supply
The standard model of the power supply producers a LOT more heat than the 231 model does.
I salvaged these two components from an old PS3. At last check, they were both still fully functional.