Here is my example everyone,
My 3 year old ASETEK skinny 120mm radiator on my AIO water cooling setup is mounted on my rear 80mm/92mm/120mm rear fan mounted by the IO shield keeps my 2600k cooler then you would think with my push pull pair of black Cougar Vortek 120mm fans on it. My 2600k is running at 4715mhz with HT on and a 46x102.5 multiplier and 1.392 volts under load....LLC is set to level 4 with idle voltage at 1.375. Idle temps are with 18c ambient case temp are 25c temps max out fully loaded 62c-65c "before removing the fan grill and 80mm,92mm mounting points Ioad temps were 67c to 71c" using IntelBurnTest V2 at very high setting since that makes your CPU hotter then running prime 95. I just removed the honeycomb fan grill on the rear of my HAF 922 case where the 120mm radiator is mounted and it dropped my temps around 5 degrees C...unbelievable how much airflow that stupid grill obstructs. I would have to say a easy 35%-50% between the honeycomb itself and the 80mm and 92mm mounting area/holes that cause a lot of blockage in all 4 corners. I am not even going to add a 3 ring un-obstructive chrome 3 or 4 wire grill but there is absolutely no need for one.
Anyone with a universal 80mm/92mm/120mm or 140mm obstructive rear fan grill on the back of your chassis I highly recommend you cut that POS out of the way. It increases air flow dramatically! Anyone running A 120MM AIO radiator with 1 fan in push or pull or 2 fan like I have in a push pull configuration cutting the grill off and the support brackets along with removing all sharp edges for looks on all 4 corners for the smaller 92mm and 80mm fan mounts will notice a drastic increase in airflow through your radiator I am sure it was blocking almost half the air coming through my radiator since temperatures dropped around 5 degrees Celsius. I wish I had a windspeed gauge so I could have measured the airflow before and after the modification.
I could see this increasing the cooling power of all 120mm radiator setups but I think the H80i will benefit greatly since the fans will not have to battle the extra thick radiator along with the restrictive fan grills.... most of the 120mm rear case mounted universally sized fan mounts are very very restrictive. Along with increasing airflow I noticed that it reduced noise since that air is not being forced through the poorly designed stamped steel/aluminum rear fan grills/mounts. The noise reduction is minimal but it does reduce it a tiny bit.
Any feedback is welcomed.