the truth is my A3 side panel is vented but very open, and i can see all the crap inside hahah, also you get a lot of component noise like when you move the moue and stuff like that.
PSU fan as zero DB setting, cooler is a NH D15 with fan fixed at 400RPM and fans are P12 silent at 50%, but as with everything it still give's of some noise and with the panel been so vented i can hear it.
i know fro xperance that adding a fan filter can block a lot of noise as it reduces the open space, so that's my plan