Hey there, since this seems the most appropriate place, I thought I'd ask you questions I have regarding airflow in the case here instead of starting a new thread.
First of all, the specs for my current build are in my sig, but basically it's in a Corsair 750D, Running a Noctua NH-D15 with stock fans and an MSI R9 290. The case is elevated off the ground, placed on a cabinet with no obstructions to intake or exhause beyond the already restrictive front panel and Demciflex filters. For fans i'm using 7 x AP-15 for all intakes and rear exhaust. The blue rectangle in the picture consists of 2 x Bitfenix Spectre Pro LEDs hung from a bracket.
All intake fans are run off a fan controller (NZXT Sentry 3) at 40% when doing day to day tasks but would be ramped up when needed. The Noctuas and rear exhaust are run off the motherboard with the exhaust having a more aggressive fan profile in order to exhaust out warm air at a higher rate. Ambient temps are around 30deg C and cooler intake temps hover around 2-3 degrees higher.
With fans in their lower settings, I get temps about 6-8 degree above ambients for my cpu but when I crank all the fans to their full rpms, i somehow get warmer temps. Could this be because I have insufficient exhausts? Or that warm air is recirculating back into the case?
Also, i'm thinking of ghetto-rigging another fan to the pcie brackets to obtain a "straighter" path of fresh air past the gpu. In your opinion, would this help in any way or would it just be a waste of time?