Have you ever wondered whether or not fancy PC coolers were really necessary or wished that your computer didn’t have any fans?
Generally, some type of PC cooler is required in order to prevent components (especially CPUs) from overheating. Without proper fan cooling, many computers will go into thermal shutdown within seconds or minutes. However, there are many of types PC cooling solutions and aftermarket coolers are usually not a necessity.
A heat sink (even with premium thermal paste) alone is usually not enough to keep your CPU (or other components) cool enough for even the lightest of use. That said, depending on your needs, it may be possible to modify your system via hardware or software to allow for operation without a fan.
In the case of hardware, the most important factor is something called thermal design power. We’ll talk about that next.
By the way: We have a helpful standalone guide to determining how hot your CPU can run. It includes tips on how to check for heat damage too.
Also: We have a full comparison of Real Temp & Core Temp software. These are both lightweight, easy-to-use applications that are great for beginners looking to monitor their PC’s temperatures.
Thermal Design Power
Thermal design power (TDP) describes the amount of heat a component will generate under a typical workload. It is specified in watts (W). When assessing your cooling needs, the TDP of your CPU is what you’ll be mostly concerned with.
For instance, if your CPU has a TDP if 195W, any cooling solution you employ would have to be able to dissipate at least that amount of heat. That means that a cooler with a TDP of 300W could handle the load, but one with a TDP of 150W could not.
Where CPU’s are concerned, a higher TDP generally equates to three things: higher performance, higher power consumption, and higher temperatures.
The more performance you need from your CPU, the harder time you will have finding a cooler that can handle the heat it generates.
With that being said, keep in mind that TDP is not a precise gauge of power consumption or performance. Rather, it’s an engineering guideline, meant to help you get a ballpark estimate of your cooling needs.
Other components, such as GPU’s, will also often have a TDP specified, but they are of less concern because those components usually incorporate their own cooling.
If you want to eliminate your fan, focus on the TDP of your CPU. From there, you can start looking for a passive cooling solution. That’s what we’ll talk about next.
Passive PC Coolers
Passive cooling means cooling without forced air, i.e. fans. It relies on natural convection to remove waste heat from the surface of the heat sink. Some heat sinks are actually designed to work passively, without a fan. To do this there are a couple of heat transfer mechanisms they use:
1. Heat pipes: These are tubes, typically made of copper, that are filled with a heat conducting liquid. The liquid absorbs heat at one end of the tube, causing it to evaporate. The evaporated liquid travels through the tube and eventually condenses, releasing its heat. The condensed liquid is then returned to its original location through capillary action.
Heat pipes have two important advantages over forced air convection. First of all, they have a much higher thermal conductivity. This allows them to be smaller than a fan while providing as-good-or-better heat transfer characteristics. For this reason heat pipes are popular in laptops. Second, they have no moving parts so in addition to being quiet, they are also generally maintenance-free.
2. Vapor chambers: These are similar to heat pipes but they are shaped like a flat slab and therefore spread heat away from the source in two dimensions. Many cell phones use vapor chambers.
In addition to heat sinks using heat pipes and vapor chambers, there are computer cases that are designed to use passive cooling in order to be completely fanless. They employ the use of heat pipes in conjunction with judiciously placed vents. Some cases actually use their walls as large, passive heat sinks!
Passive cooling is an elegant solution but it has its limits. You should research the various heat sinks and specialized cases available and use tools such as thermal design power to determine if they can provide adequate cooling for your chosen CPU.
If you can’t make passive cooling work in your system, there is another, more powerful fanless solution: liquid cooling.
Liquid PC Coolers
Liquid cooling uses a system of tubes filled with water or another liquid to conduct heat away from the CPU. The liquid is pumped through the system and ultimately through a radiator, where the waste heat is dissipated.
Like heat pipes and vapor chambers, liquid cooling exploits the superior thermal conductivity of liquids to eliminate the need for forced air.
In fact, liquid cooled systems can eliminate more waste heat than any forced air system. For that reason they are often used in high-end gaming rigs, video editing systems, and other high-performance systems.
Some drawbacks of liquid cooling include increased complexity and the possibility of a coolant leak.
If passive cooling and liquid cooling can’t get you the results you need, there’s an even more powerful, albeit more expensive, solution: phase change cooling.
Phase Change Coolers
Phase change cooling is somewhat like having a refrigerator inside your computer case.
The physics of phase cooling are similar to the way a refrigerator works, with liquid being compressed, evaporated, and condensed while absorbing and dissipating heat from the CPU and other components. It’s a powerful cooling method that can create temperatures as low as -100C!
The drawback is that it creates condensation inside the computer case which must be managed. For that reason, phase change cooling is generally only employed in very high-end, high-performance systems.
Passive cooling, liquid cooling, and phase change cooling can be very effective mechanical solutions to eliminating the need for a fan, but there are other ways to do it too. One such method is soft cooling.
Soft cooling refers to the practice of using software to modify the performance of your system such that your CPU only works as hard as you need it to, but no harder.
As we know, the harder a CPU works the more heat it generates. By dialing down performance at times when you can tolerate it, you’ll lighten the demands placed on your cooling system.
One soft cooling method is undervolting.
Undervolting is another way to reduce the power used by your CPU, and therefore the heat generated by it, when you don’t necessarily need the extra performance.
Undervolting reduces the voltage supplied to the CPU by the motherboard. It’s typically configured in your BIOS (Basic Input/Output System), but there are also software programs available to manage it.
Other soft cooling methods involve controlling halt instructions, which is turning off various components when they are not in use or putting them in a low-power, standby mode.
Despite its catchy name, soft cooling isn’t really cooling, but rather a reduction in heat creation.
The Future of PC Cooling
As the power and performance required by computer systems continues to increase, fans are becoming less and less effective in providing the amount of cooling needed. Scientists and engineers are always looking for ways to design more efficient, capable cooling systems.
Exotic substances such as liquid nitrogen are already being used in some supercomputers. Phase change cooling is another area where lots of advances are being made.
Even more fanciful ideas are currently under development, including systems that take advantage of other physical phenomena such as the corona discharge effect, which uses ionized air to transfer heat out of a system.
Another idea being explored is how to incorporate cooling within the CPU itself.
One such approach is to fabricate “micro-channels” into the CPU and pump coolant through them. Another approach is “jet impingement cooling”, in which coolant is flowed through a small orifice to form a jet that sprays the CPU.
As CPU power densities increase these ideas becomes more and more attractive.
As these solutions become more mainstream they may work their way into consumer grade products. Who knows, maybe your next CPU will come with a passive, liquid nitrogen-based heat sink or an electrostatic fluid accelerator!
After reading this article, you may be surprised that it is indeed possible to adequately cool a CPU without a fan. What’s more, there are a variety of ways to do it.
By understanding and applying thermal design power, you may be able to find a cooling solution that works for you. Whether it be a passive heat sink utilizing heat pipes or vapor chambers, a specially designed passive cooling case, or a water cooling system, quiet, effective options are available.
What’s more, software can also be a powerful tool to help with cooling. Soft cooling techniques like undervolting and halt instructions can avoid wasted power which would otherwise contribute to unwanted heat.
Finally, keep an eye on the market, because new and impressive cooling technologies are always on the horizon.