When it comes to buying a radiator for your custom loop, there are a few areas to consider first. You are going to want to ensure you maximize the cooling potential of your water cooled PC and keep those temps as low as possible, without any extra work. PC radiators come in all sorts of different sizes and vary in thickness too. In this section, we will go over a few of these key areas, so hopefully, you walk away with the best product for the job.
What Is a PC Radiator?
The radiator is going to be responsible for cooling the liquid in your loop. A radiator achieves this by exchanging heat with the surrounding air that is stored in its stacks of copper fins. Cool air is usually forced through the fins, making contact, and dissipating the heat.
As you can imagine, the effectiveness of your loop depends on surface area. The more surface area, whether that is through a large radiator or a couple in your loop, is going to remove heat from your liquid more efficiently, leaving you with a cooler system. Of course, there will start to be diminishing returns but finding your optimal cooling capacity is all part of the process and extra radiators could allow for slower RPM fans and a quieter running system.
How Big Should My PC Radiator Be?
So a common rule of thumb many prospective water coolers will live by is the 120mm/140mm per component rule. Take this with a pinch of salt though, it isn’t an exact science, more of a minimum recommendation. This rule doesn’t really take anything else into consideration. If you are overclocking, for example, you are probably going to want to double this rule to ensure you give the cooling solution the headroom it needs.
The most important factor when choosing a radiator is how much surface area you can fit into your chosen PC case. For example, a slim radiator with a larger surface area is going to be your best choice, however, if you can’t fit more surface area you can rely on a thicker rad instead.
Radiator Thickness & FPI (Fins Per Inch)
The thickness of your radiator is typically the second most important factor to consider. If you can’t fit a lot of rad space, you can go thicker. Your standard radiator thickness is 30mm, they don’t go thinner than this but ideally, you are going to want a 60mm thick radiator with an optimal fan setup.
As you can imagine, a thicker radiator will require higher speed/ pressure fans but either option is going to be beneficial so you need to base this decision on what you can fit.
FPI stands for “fins per inch” and is basically a standardized measurement unit for the density of the fins present in your radiator’s core. The higher the FPI, the higher the cooling potential of the radiator, as it can take out more heat from your loop at any given time.
Higher FPI rads increase the air resistance when cooling though, so you need to ensure you have the optimal fan setup to push/pull the air through the dense array of fins, which in turn also brings about extra noise concerns as the air doesn’t have a clear cut path through the radiator.
Radiator Fans: Push, Pull, or Push-Pull?
The size of the fans is determined by the size of the radiator, for example, a 280mm radiator is going to be able to fit two 140mm fans, and a 360mm radiator is going to be able to fit three 120mm fans, and so on.
High-speed fans work well with fin dense rads, whereas your low-speed fans are better when paired with low fin density radiators. This doesn’t mean that you need to have a low fin per inch radiator and low-speed fans, as higher airflow fans are going to yield better thermal results.
In terms of fan configuration there are three: push, pull and push/pull. A push configuration is where the fans are mounted in front of the radiator and push the hot air through it. Pull, as you can imagine, is the opposite, with the fans behind the radiator pulling the air through it. Push-pull is a combination of both where the fans are on either side of the radiator, essentially sandwiching it.
Push-pull is only ever used when a thick radiator or high FPI increases the heat dissipation surface. This is because a push or pull configuration may struggle to blow the air through the dense radiator, resulting in a poor cooling solution.