I swapped my two NZXT AER exhaust fans in my H500i with a Noctua NF-A12x15 120mm PWM (back) and a Noctua 140mm NF-A14 PWM (top). CPU is a few degrees cooler, but
Amazon.com: Noctua 140mm Premium Quiet Quality Fan with AAO Frame Technology (NF-A14 PWM) : Electronics
Water Cooling Rradiator Fan | Noctua 140mm Cooler | Noctua Cooling Fans - Nf-a14 14cm - Aliexpress
Noctua introduces NA-IS1 inlet spacers for suction applications and NA-SAVG2 gasket set