One of my gripes about the Q500 - and many other cases, for that matter - is that the plastic front bezel really prevents the front bottom fan from drawing in outside air, for two reasons.
First, there is very poor venting in that faceplate. Less obviously, there is a gap of about 1.25 inches between the plastic faceplate and the steel front of the case itself. That means that the intake fan (moutned inside the steel front) is pulling air out of that space, not directly from outside. Meanwhile, that space is filling up with hot air that comes from the many spaces in the steel case front up by the drive bays. You wind up recycling warm case air more than actually drawing in cool outside air.
I've used a two-fold fix. First, I drilled a 6" grid of roughly 1/4" holes (about 1/2" apart) into the lower front of the plastic bezel. Next, I cut a piece of foam-core board to go between the plastic bezel and the steel case front just above the fan grill. This separator (duct taped in place) prevents air from up by the drive bays from recycling down through the dead space to the intake fan. Essentially, it creates a (very short) duct from the fan to the outside air source.
It was a cheap fix, and my airflow (and temps) have improved quite a bit. Taping up the vent holes in the side panel also helps airstream integrity through the case.
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