I need some help from the cooling and silence gurus. Here is my current airflow setup:
The green arrows represent air coming in and yellow arrows is air leaving. The problem is, my PC sits in a TV stand with very little space around the edges. As depicted, there are 2-inches on each side, 3-inches to the rear, and 1.5-inches above. The 120mm fans are Scythe 120mm (SY1225SL12LM-P) for quiet, efficient cooling. There are two 80mm exhaust grates and a single "air" grate in the top-rear of the case, so air escapes through it as well (not shown in image). Last, I'm using the Intel stock cooler (NH-L12 ordered this morning) and the stock fans on the MSI R7850. I should mention the TV stand has a 4cm hole centered behind the PC for all the wires.
My problem is keeping the system cool after an hour or so of gaming. The temps aren't out of control, but as my gaming session goes on, the system gets louder and louder in order to keep the load temps down. Temps at stock are around 64C (CPU) and 70C (GPU). The ambient temp is around 26C (live in Hawaii). I plan on OC'ing in the future, but want to get all the stock temps a little lower first and ensure the overall cooling is efficient (especially around the GPU). The other issue I'm having is getting the hot air of of the TV stand (or at least off the bottom shelf).
Is there any way to make the cooling more efficient while maintaining a certain level of silence? Would adding a single 80mm exhaust fan in the rear help? Would a PCI slot cooler help? Regardless, I HAVE to ensure the system is rather quiet since my wife and kids use it to stream stuff.
Sorry for the long post. Any help is greatly appreciated.