Whether the fans are intake, or exhaust, they need a certain amount of distance behind and in front of impeller, or the blades will stall, and it will barely move any air. I recommend checking each fan fed the intended voltage, physically moving them toward and away from restrictions ahead of and behind the flow, as its rpm and blade design have huge effects on how much air is moved and how much noise is made.
If one has to have restriction, have it in front of the fan, rather than behind.
Even moving the finger grills away from back side of fan by 8mm greatly improved airflow and reduces noise. Same is true in front of the fan, but to a lesser degree, in my experience.
Those dust filters attached to fan, pretty much make the fan useless, unless making noise is the objective.
Alternatively, are the fans really needed? Most kweld setups dont have/need any active cooling. (But if it’s for the cool factor, I’m here for it. Pun intended)
Good point. 