Upgrading parts of pc. I have 2 rads 120x2 rad 140x2 rad At the moment I think I have these style of fans. https://www.pccasegear.com/products/20514/corsair-air-series-af120-quiet-edition-case-fan-twin-pack which is 40cfm @ 21dB 1 is dead, the other is on its way. So I was looking at https://www.pccasegear.com/products/37647/be-quiet-silent-wings-3-120mm-fan which is 50cfm @ 17dB or https://www.pccasegear.com/products/37646/be-quiet-silent-wings-3-120mm-fan-high-speed-edition which is 73fcm @ 28dB I was looking at up using them at max speed all the time. My pc is on 24/7 is 28dB loud, I think it would be the best, but I sort of like a lower noise computer. any other options? I haven't used a PWM fan at all yet.