Why only a delta T of 10C in a loop?

Khilan Santoki

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Jan 31, 2015
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I have read many forums telling that we should have a delta T of Minimum 10C and not more, The lower the better. Delta T is the difference between the water and ambient air when equilibrium is established and I want to take two cases, One where delta T is high i.e the water temp is quite high then the air temp, According to law of Conduction the rate of heat transfer is directly proportional to the temp difference hence the heat transfer from the water in radiator and air would be faster and a bit slow for Cpu to loop, As the there wont be much of a temp difference in the Cpu temp and loop temp.If the delta T is small i.e the loop temp is not as much higher than the room temp, So the transfer of heat from the water in rad to air would be slow and high transfer rate from Cpu to loop water.So then we should have a balance of delta T not High not low why is it not so?
 
there is no such thing of what the delta T should be for the liquid. simply put, you want the lowest liquid temps to maximize the heat transfer from components (CPU, GPU etc.) to the liquid.
eventually the loop performance (how much heat it can dissipate) is mainly determined by total rad size and fans.
If the liquid is just few degrees above the ambient and the components are within desired temp range, it's a good reason to lower the fans speed to lower the noise level. for example it's not really important if an overclocked to the max intel CPU under load is working at 50C or 70C.
Each device has it's own desired range. I found that the max clocks on my GTX 1070 can be achieved under 50C. So I really don't mind the GPU sitting at 45C while gaming, though I can get it to under 40C at the cost of much higher noise.
Of course you can't have the liquid temp = air temp as no heat transfer could happen. and the closer they get, rad surface needed to dissipate the same amount of heat is growing exponentially.
Many things that you see on forums are just myths/misconceptions/plain stupidity. Even in 2017 some people still think that loop order matters or that liquid cooling will lower the heat output of the computer. Well,they kinda true, but so insignificantly as it's only about 1C max temp difference in a proper loop for the former and the delta of current leakage levels at not much different temps for the later.
When you dive into more sophisticated subjects, it starts to be really hard to find reliable info unless you have taken a couple of courses in thermodynamics :)
 

Then why a lower delta T is more Efficient?