Liquid Cooling Thermostat

Hello Fellow Enthusiasts,

I've often wondered if liquid cooling for computers uses a thermostat or something with the same function..

For those who don't know; in an automobile a thermostat throttles coolant flow long enough for the radiator to dissipate the heat.
Without a thermostat, the coolant flow is constant through the radiator an it cannot dissipate the heat; causing the engine to overheat.

So is a thermostat needed on a computer liquid cooling system? Is the flow controlled by a radiator exit orifice smaller than the entrance orifice? How is the coolant flow controlled?

I ,obviously, have never owned a computer with liquid cooling and wonder how it works. Any input would be helpful   

hoserator,

Yes, I realize the auto thermostat brings operating temps up or down to the temp rating on the thermostat depending on ambient temps.

It makes sense that the computer cooling system only needs to bring temps down but I am confused about what "with loads it only goes up"? Does "it" mean the RPM, power draw, pump pressure or do you mean temp goes up with load and the coolant flow is constant without any adjustments?

If the latter is the case, then too much load (overheating of components} can only be cured by installing a larger capacity radiator, faster fans, or refrigerating the coolant? Are the radiator fans on these units controllable or do they run full speed always? Just wondering.....thanks for your replies

In a computer water cooling loop, you want the coolant always flowing in the system, otherwise the components will quickly overheat and either throttle down or turn off completely. Unlike cars, you do not need the computer to warm-up to an operational temperature, so there is not a need to turn the loop off at any point. Measuring coolant temperature is just a means to handle overall system temperatures.

There are both plugs and pass-through thermal resistors (standard 10K Ohm @ 25°C) for measuring coolant temperature.





While it isn't necessary to measure coolant temperature, it is an alternative method that can keep fan speed more consistent, as the coolant temperature in the machine will fluctuate less than the components. You'll want to keep the coolant temperature low enough to have substantial difference in temperature between it and the components you're cooling, but the coolant temperature going into the water pump will probably be the limiting factor at 60°C maximum.

Certain boards, like Asus' ROG boards may have two-pin headers for the 10K Ohm sensors, but you can also go with a stand-alone system, like DS' fan control board, Lamptron controller, or Aquacomputer Aquaero. I just got the Aquacomputer Aquaero 6 LT for my build the other day to measure the coolant temperature at all the points in the loop, as well as ambient air temperature (one method to control loop temperature in a consistent way is to keep the delta T between the coolant and ambient air at a target amount).

Many thanks to bprat22, hoserator, Alex, and especially "No Name" for the informative replies.

Now I think I have a pretty good idea how the liquid cooling works.