So you let the fans spin up instead of being a silent king?Ditto on the cool air in and additional fans as exhaust or if you can push in enough cool air to satisfy the exhaust needs. Pumping warm air from one rad up and through another will still cool somewhat but cool air to all does the best job. My Delta Idle is 6C idle and tops out at 8C under heavy load. I could get the idle lower but fans are controlled on a curve with aquaero using liquid temp as a reference with a min of 28C (minimum fan speed for 28 an under) and max of 32C where fans will slowly ramp to full speed at 32C. They seldom make full speed but If Im really loaded on a 10980XE and 2x 2080Tis it will get pretty close. Real question is whats your delta on the liquid cooled devices? My GPUs max out at 8C delta where my CPU will hit 40C delta and sometimes a little more. Right now at Idle GPU delta is 1.8C and CPU is 7.2C.
Either way my liquid temp never passes 32C. Right now liquid temp is 28C with fans at 40% and ambient at 24C.