Cpu coolers generally come in two varieties.
Liquid cooled cpu fan direction.
So flip the fan and run it as an updraft.
You have the reservoir the pump the radiator the fans some tubing a block for either.
The coolant is specially developed to bring the best light dispersion capabilities withing various pc liquid cooling products.
If you have a large aftermarket cpu cooler it probably has one or more fans of its own.
Best liquid cpu cooling.
Overall though liquid cooling tends to generate less.
This includes measuring how much a front radiator might reduce cpu temperatures at risk of raising gpu temperatures or how a top mount might do the opposite.
In the very least we can look at liquid cooler placement performance in a few different cases.
Liquid cooling especially when using an all in one aio tends to be quieter than the fan on a cpu heatsink.
All fans will be configured to 100 in our testing.
Water cooling systems whether they are a custom loop or an aio all follow the same basic principles.
Again this can vary in that there are air coolers with fans specifically designed to reduce noise and fan settings or fan selection can impact the amount of noise generated.
An interesting test would be to measure the difference that occurs when you reverse the fan direction of such a cooler.
A side mounted fan expelling or drawing in air in a direction perpendicular to the motherboard might be useful here but not all cases support that.
The first is an air cooler which comes with a big metal heat sink and a fan that pulls air away heat from the cpu.