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CoolIt Systems Freezone Peltier CPU Cooler Review

Author: Lee Garbutt
Manufacturer: Coolit Systems

How It Works...

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The main difference between the Freezone CPU Cooler and a traditional PC water-cooling system is that instead of using a radiator to cool the circulating water, the Freezone uses a Thermoelectric Cooler (TEC) based chiller.



Typical PC Water-cooling System


In a conventional PC water-cooling system, waste heat from the CPU is transferred into the water by the waterblock and then into the air by the radiator.  One or more fans are typically used to force air thru the radiator to increase heat transfer.  A small pump circulates water thru the system to transport heat from the waterblock to the radiator.  When using a radiator, the water temperature can never be cooled below the temperature of the air flowing thru it (and the CPU can never be cooler than the water).  In most PC water-cooling systems the average water temperature will always be 2ºC to 10 ºC above the ambient air temperature.  As a result the CPU can never be cooled below ambient.



Freezone CPU Cooler


Instead of a radiator, the Freezone system uses MTEC technology (Multiple TECs) to actively chill the water.  Six Peltier devices pump heat out of the water and then dissipate the heat via an air-cooled aluminum heatsink.  The warm exhaust air is directed out the back of the PC enclosure.  The pump circulates water thru the system to transport heat from the waterblock to the chiller module.



Freezone Chiller


The Freezone component that at first glance looks like a radiator is the MTEC chiller.  Three Peltier devices are mounted on the top of the chiller and three more are mounted underneath; sandwiched between two waterblocks and a rectangular heatsink in the middle.  Each Peltier device pumps heat out of the water and into the air-cooled, central heatsink.  Because the Freezone chiller uses active cooling instead of forced air convection cooling, the water can easily be cooled below ambient.


A Thermoelectric Cooler is a solid state device that operates on the Peltier effect.  When a DC voltage is applied to an array of tiny thermocouples sandwiched between two ceramic plates, one side of the device becomes hot while the other side becomes cold.  The TEC acts like a solid state heat pump and can be used to actively cool (or heat) an object it is attached to.  In the Freezone water chiller, six TECs are used to actively transport heat out of the circulating water and into a large heatsink that is cooled by a fan. 



Peltier Device or Thermoelectric Cooler (TEC)


Peltier devices are pretty cool little bits of technology but they are not without their disadvantages.  One problem with incorporating one or more TECs into a HSF or water-cooling system is that Peltier devices are not very efficient.  This means they consume more energy than they can pump — two or three times more, which is converted directly into waste heat that must be dissipated on the hot side along with the heat being pumped.  This can place a very heavy heat load on a single air-cooled heatsink.



CoolIt Systems has wisely designed the Freezone water-chiller using six relatively small TECs instead of one or two large Peltier devices.  Multiple TECs operating at reduced voltage are much more efficient and generate significantly less waste heat than one or two larger TECs operating at their maximum capacity.


Another potential problem when using TECs in a PC cooling application is that as the CPU load changes the temperature may change dramatically.  At light idle loads the CPU waterblock and surrounding CPU socket area may become so cold that condensation and even frost may form — not good.  As the heat generated by the CPU increases, the TECs become less effective.  If the heat pumping capacity of the TECs (Qmax) isn't sized to handle the maximum CPU heat load, they won't be able to keep up, resulting in over heating and instability.  The Freezone CPU cooling system uses a Thermal Control Module to regulate the water temperature and prevent it from getting too cold, so condensation is not a problem.  By regulating power to the Peltier devices and the cooling fan, the controller also helps conserve energy and minimizes noise.


June 7, 2014 | 02:04 PM - Posted by Bogdan (not verified)

This are aluminium waterblocks, and aluminium sucks. Im in process of making a device like this but with 6 TECs all runing at full load at 12V from a separate power supply. On top of that I will use all copper waterblocks for best thermal conductivity. I think I will achieve some crazy results. Will probably have to undervolt TECs if CPU is idling.
Great testing btw, and great reference results.