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pelvis_3 · 05-10-2005, 02:20 AM

Some information on Peltier Based Cooling.

What is a peltier cooler?
A peltier cooler or 'Thermo Electric' is a cooler that uses a peltier element (TEC). Peltier coolers consist of the peltier element itself, and a powerful heatsink/fan combination to cool the TEC.

Peltier basics
The typical maximum temperature difference between the hot side and the cold side of a TEC,is around 70°C.
Does this mean that simply adding a peltier element between heatsink and the CPU will cause the temperature of the cooled device to drop by 70°C? No, that would be too good to be true.

Imagine that you are cooling a CPU with a power usage of 35W, using a regular heatsink. Will the temperature drop if you add apeltier element between CPU and heatsink? No. For a simple reason: In addition to transporting heat, peltier elements also emit considerable amounts of heat.

So, the heatsink will have to dissipate substantially more heat than before, and will get much hotter.
Peltier elements have very low efficiency. They will consume more power than they transport! Actual peltier elements may consume twice as much energy as they transport heat. So, if you are using a peltier element, the heatsink it is used with must be much more powerful than a heatsink used for cooling a heat source without peltier element.

Do not confuse the maximum amount of power a peltier element can transport with the maximum amount of power usage of the peltier element. Some retailers sell "80W peltier element", without stating what this value actually means. This is misleading - what you want is a high transport capability, but a low power consumption.

Peltier elements come in various forms and shapes. Usually, they consist of a larger amount (e.g. 133) of thermocouples arranged in rectangular form, and packaged between two thin ceramic plates. The commercial TEC unit of interest for PC geeks is a single stage device, about 4 - 6 mm thick and somewhere from 15 to 40 mm on a side.

The TEC will have two wires coming out of it, if a voltage is applied to those wires, then a temperature difference across the two sides is achieved, if the polarity is reversed on the wires - then the temperature difference is also reversed. The TEC is placed in between the CPU/GPU and the heatsink with appropriate thermal interface materials. So one thing i might note is that if the voltage is applied in the wrong direction then the TEC will cool your heatsink and heat your CPU!

Peltier elements come in padded and non-padded versions. On non-padded peltiers, the thermocouples are visible from the side. On padded peltier elements, you can only see the padding material (often silicon) from the side.

Problems related to peltier cooling
As mentioned above, high power usage and high power dissipation are the biggest problems related to peltier cooling. In the days of first-generation Pentium CPUs, readymade peltier/heatsink combinations were widely available, which could be installed and used just like a regular heatsink.

For today's CPUs having a power dissipation of over 100W, building a Peltier CPU cooler using just a peltier element and a heatsink is quite a challenge, and ready-made peltier coolers are scarce and expensive. With such coolers, over 200W of heat may be dissipated inside the case. For modern CPUs, it is better to combine peltier elements with watercooling. In any case, the resulting cooling system will be expensive to run, due to its high power usage, and not very eco-friendly. The large power dissipation will require powerful fans.

Also, keep in mind that if the cooling of the peltier element fails, the results will be more disasterous that if a conventional cooling system fails. Even if your CPU has a thermal protection that will cause it to shut down if the temperature gets too high, the peltier element may still kill it by continueing to heat it up long after it has shut itself down.

Another problem related to peltier cooling is condensation. Since it is possible to cool components below ambient temperature using peltier elements, condensation may occur, which is something you'll definitely want to avoid - water and electronics don't mix well. The exact temperature at which condensation occurs depends on ambient temperature and on air humidity. There are some models of Peltier Cooling available that don't let the CPU cool below 28*C to prevent condensation.

Advantage of peltier elements
There is not really much to say here except These coolers kick ass in most cases providing you understand the disadvantages to Peltier Cooling so you can fully understand the advantages!

After having focused on problems related to Peltier cooling, let's not forget about their biggest advantage: They allow cooling below ambient temperature, but unlike other cooling systems that allow this (vapor phase refrigeration), they are less expensive and more compact. Peltier elements are solid-state devices with no moving parts; they are extremely reliable and do not require any maintainance but can be fairly expensive. That being said they are not for the faint of heart. If you are not a die hard overclocker then this might not be the way to go and should probably stick with Stock or aftermarket Air cooling!

05-10-2005, 02:20 AM	#3 (permalink) Top
pelvis_3 HWF Member For Life Join Date: Jul 2005 Age: 22 Male Posts: 2,336 Times Helpful: 265 My Mood: Happy Status: Offline My Computer	Some information on Peltier Based Cooling. What is a peltier cooler? A peltier cooler or 'Thermo Electric' is a cooler that uses a peltier element (TEC). Peltier coolers consist of the peltier element itself, and a powerful heatsink/fan combination to cool the TEC. Peltier basics The typical maximum temperature difference between the hot side and the cold side of a TEC,is around 70°C. Does this mean that simply adding a peltier element between heatsink and the CPU will cause the temperature of the cooled device to drop by 70°C? No, that would be too good to be true. Imagine that you are cooling a CPU with a power usage of 35W, using a regular heatsink. Will the temperature drop if you add apeltier element between CPU and heatsink? No. For a simple reason: In addition to transporting heat, peltier elements also emit considerable amounts of heat. So, the heatsink will have to dissipate substantially more heat than before, and will get much hotter. Peltier elements have very low efficiency. They will consume more power than they transport! Actual peltier elements may consume twice as much energy as they transport heat. So, if you are using a peltier element, the heatsink it is used with must be much more powerful than a heatsink used for cooling a heat source without peltier element. Do not confuse the maximum amount of power a peltier element can transport with the maximum amount of power usage of the peltier element. Some retailers sell "80W peltier element", without stating what this value actually means. This is misleading - what you want is a high transport capability, but a low power consumption. Peltier elements come in various forms and shapes. Usually, they consist of a larger amount (e.g. 133) of thermocouples arranged in rectangular form, and packaged between two thin ceramic plates. The commercial TEC unit of interest for PC geeks is a single stage device, about 4 - 6 mm thick and somewhere from 15 to 40 mm on a side. The TEC will have two wires coming out of it, if a voltage is applied to those wires, then a temperature difference across the two sides is achieved, if the polarity is reversed on the wires - then the temperature difference is also reversed. The TEC is placed in between the CPU/GPU and the heatsink with appropriate thermal interface materials. So one thing i might note is that if the voltage is applied in the wrong direction then the TEC will cool your heatsink and heat your CPU! Peltier elements come in padded and non-padded versions. On non-padded peltiers, the thermocouples are visible from the side. On padded peltier elements, you can only see the padding material (often silicon) from the side. Problems related to peltier cooling As mentioned above, high power usage and high power dissipation are the biggest problems related to peltier cooling. In the days of first-generation Pentium CPUs, readymade peltier/heatsink combinations were widely available, which could be installed and used just like a regular heatsink. For today's CPUs having a power dissipation of over 100W, building a Peltier CPU cooler using just a peltier element and a heatsink is quite a challenge, and ready-made peltier coolers are scarce and expensive. With such coolers, over 200W of heat may be dissipated inside the case. For modern CPUs, it is better to combine peltier elements with watercooling. In any case, the resulting cooling system will be expensive to run, due to its high power usage, and not very eco-friendly. The large power dissipation will require powerful fans. Also, keep in mind that if the cooling of the peltier element fails, the results will be more disasterous that if a conventional cooling system fails. Even if your CPU has a thermal protection that will cause it to shut down if the temperature gets too high, the peltier element may still kill it by continueing to heat it up long after it has shut itself down. Another problem related to peltier cooling is condensation. Since it is possible to cool components below ambient temperature using peltier elements, condensation may occur, which is something you'll definitely want to avoid - water and electronics don't mix well. The exact temperature at which condensation occurs depends on ambient temperature and on air humidity. There are some models of Peltier Cooling available that don't let the CPU cool below 28C to prevent condensation. Advantage of peltier elements* There is not really much to say here except These coolers kick ass in most cases providing you understand the disadvantages to Peltier Cooling so you can fully understand the advantages! After having focused on problems related to Peltier cooling, let's not forget about their biggest advantage: They allow cooling below ambient temperature, but unlike other cooling systems that allow this (vapor phase refrigeration), they are less expensive and more compact. Peltier elements are solid-state devices with no moving parts; they are extremely reliable and do not require any maintainance but can be fairly expensive. That being said they are not for the faint of heart. If you are not a die hard overclocker then this might not be the way to go and should probably stick with Stock or aftermarket Air cooling! __________________ Adopt an unanswered thread. \| Who's Online \| vB Code Some people are alive only because it’s illegal to kill them! Support bacteria, it's the only culture some people have!