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Why My PSU Fan Going UP and Down? How to Install?

While components like your motherboard, CPU, GPU, RAM, and storage drives are one of the most important aspects of a computer that decide its performance and performance, you should know that the PSU powering all of these units and more is even more important when it comes to the stability of the system. Without a proper PSU, none of the components in your system would get a proper power supply, resulting in bad performance and a frequency of system crashes. The problem is even more severe when it comes to gaming computers where almost all components require a lot of power to operate.

Therefore, almost all gaming or creativity-focused PC builds are equipped with a high-capacity PSU. Right now, PSUs offering 800 Watts power output, or more, are very common and very critical for PCs powered by top-of-the-line GPUs such as Nvidia RTX 3080 or RTX 4080. But with such high power output capacity, PSUs also generate a lot of heat and must be cooled down in order to maintain their performance. Therefore, all PSUs are coupled with a dedicated cooling fan. If you are also installing a new fan for your PSU, or replacing a damaged one, you should go through our guide where we will discuss the importance of these fans and the proper orientation of PSU fans.

Do PSUs Need Cooling Fans?

PSU cooling fansBefore we get to the installation part of the PSU fans, let us try to understand why you need PSU fans and why it is important to choose the perfect PSU fan for your PSU if you want the best performance out of your system. PSUs generally have a built-in cooling fan to help dissipate heat generated by the components inside the unit. The fan helps to keep the PSU operating at a safe temperature and prevents damage to the components inside.

As for the heat and temperature levels of the PSU, it is a result of converting the AC power from the external outlet to the DC power needed for the PC’s internal components. The amount of heat generated is proportional to the amount of power being drawn by the PC. As a result, the PSU’s fan speed is typically controlled based on the power draw, or the PSU temperature indirectly.

The factory cooling fan of a PSU is usually located at the back of the PSU and helps to draw cool air in through vents on the side or bottom of the unit and exhaust hot air out of the back. Some high-end PSUs also have a feature called “fanless mode” which allows the fan to turn off completely when the power draw is low, and only turn on when the temperature reaches a certain threshold, making the system a lot quieter.

What Kind Of Fans Are Installed On a PSU?

Right now, there are a variety of options available for cooling fans designed for a PC. You will find many different options for case fans or fans available for a CPU cooler. However, the best option for a PSU has always been a DC brushless fan. DC brushless fans are usually preferred for PSUs because they are relatively quiet, efficient, and have a long lifespan. These fans use a brushless motor to rotate the blades, which are designed to push air through the PSU and out the back.

The size of the fan used in a PSU can also vary, but the most common sizes that you would see on a lot of PSUs these days are 80 mm, 92 mm, and 120 mm. The size of the fan can affect the amount of airflow and noise level. Generally, larger fans can move more air at a lower speed, which results in lower noise levels compared to smaller fans that need to spin faster to move the same amount of air. However, larger fans can also cause a lot of trouble when it comes to installation. For almost every single PSU, you won’t be able to install a fan that is larger than the socket available for its installation.

Some high-end premium PSUs also use fans with additional features such as hydraulic or magnetic bearings, which are designed to reduce operational noise and increase the lifespan of these fans. Additionally, some PSUs have modular cables and fans that can be replaced or upgraded if needed.

Importance Of  PSU Fan Orientation

Now comes the most important part of installing a PSU fan, its orientation. Even if you find the perfect fan for your PSU which is designed for the unit and fits perfectly in its place, it can still make a lot of differences in performance based on the orientation of the fan. The PSU fans are designed to be located at the bottom of the unit to pull air into the PSU from the surrounding environment and exhaust it out of the back. In a standard ATX PC case, the PSU is also mounted at the bottom of the case, which means the fan is almost always facing downwards.

If the PC case has a vent or filter on the bottom of the case, then it is recommended to mount the PSU with the fan facing downwards. This orientation allows the PSU to draw in cool air from the bottom of the case and exhaust hot air from the rear section, which can help improve the overall cooling performance of the PC. And the filter also helps to keep the dust and dirt intake to a minimum, keeping the PSU safe from external damage.

But, if your PC case does not have a vent or filter on the bottom, it may be better to mount the PSU with the fan facing upwards. This orientation allows the PSU to draw in cool air from the top of the case and exhaust hot air from the bottom or rear of the case. In this case, It is important to ensure that there is adequate clearance between the PSU and any components above it to avoid overheating. Also, you need to make sure that any dangling cable from internal PC components does not come in contact with the PSU fan.

How Should You Install A PSU?

Even though a lot of PSUs come with a rigid external casing with a built-in fan, it is very crucial to know which is the best way to mount your PSU in the case, especially when it comes to the fan orientation. A lot of you would be surprised to see the difference in results after the correct PSU installation. Another thing to keep in mind is that since these fans are so powerful, a lot of PSU fans also help to minimize the overall temperature of the PC case if installed correctly.

1. PSU Fan Point Up

There are some newer PC case designs available on the market that features a PSU shroud instead of the standard slot to install the unit like traditional options. And with many of these shrouds, you will also notice the lack of ventilation or grills, suggesting the better way to install the PSU is with its cooling fan facing upwards.

Otherwise, the intake air supply of the PSU will be completely blocked and the cooling fan will perform as well as when it’s turned off, excessively increasing the temperatures of the PSU. And in some cases, it usually becomes an advantage to keep the PSU fan facing upwards as it draws warm air from your system and pushes it out from the back, helping you to keep the case temperatures to a bare minimum level. It is also a better option if you are keeping your cabinet on a carpet or thick rubber mat that can block the intake of the PSU fans.

2. PSU Fan Point Down

As you may already know, almost every single famous PC case design on the market follows a similar standard design and allows you to install the components in a similar fashion. With that, you will also notice vents at the bottom of the PSU slot, indicating that the correct way to install the CPU in such a case is the fan pointing downwards. It allows your PSU to draw clean air from the bottom of your case to maintain its temperature. But, make sure that you clean the bottom filter of your case regularly. If there is excessive dirt on the filter, it will hamper the flow of air and cause the PSu temperature to increase.

What Are The Benefits of Keeping The PSU Fan Up/Down?

Benefits of keeping PSU Fan Up

  • It can increase cool airflow into the PSU from the top of the case, which may be beneficial in cases where the ventilation openings are located at the top.
  • It is suitable for cases with limited space at the bottom or cases that do not have dust filters at the bottom.
  • It can help reduce the accumulation of dust and debris in the PSU, as the fan is not directly exposed to the flooring.
  • It can help create positive air pressure inside the case, which can help prevent dust and other particles from entering through gaps and openings.
  • May be more aesthetically pleasing, as the PSU label and branding are usually visible in this orientation.

Limitations of keeping PSU Fan Up

  • It may cause the drawing of warm air from the PC components, which can increase the temperature levels of the PSU itself.
  • It may cause the PSU to be louder, as the fan needs to work harder to pull air from the PC components, considering there isn’t as much air present on the inside of the case as outside.
  • Not suitable for cases with high-end graphics cards or other components that generate a lot of heat near the PSU.
  • It causes the PSU to become top-heavy, which can affect the stability of the case if it is not properly secured.

Benefits of keeping PSU Fan Down

  • It helps to draw cool air from outside the case, which can improve the cooling performance of the PSU and other components, especially if the case is located in an air-conditioned room.
  • May help reduce the noise level of the PSU, as the fan does not need to work as hard to draw air from outside the case.
  • It can help reduce noise and vibration from the PSU fan, as the fan is not directly exposed to the PC components.
  • More suitable for cases with large CPU coolers or other components that occupy a lot of space at the top of the case.

Limitations of keeping PSU Fan Down

  • May draw dust and other particles from the floor or carpet into the PSU, which can clog the fan and reduce its efficiency over time.
  • Not suitable for cases with ventilation openings at the top or for cases that have limited space at the bottom.
  • Require frequent cleaning of the PSU fan and filter to maintain optimal airflow.
  • Suitable for cases with limited clearance at the bottom or for cases that are placed on carpet or other surfaces that may block the ventilation openings.

PSUs Need Cooling Fans FAQs –

1. What should be the orientation of PC fans?

Ans: The orientation of PC fans depends on their location and design. But, here are some general guidelines that you can follow while deciding the ideal orientation for your PSU.
Understand the design of the case and check the airflow to visualize the ideal intake position for the CPU. In some cases, it can be from the bottom whereas the top facing is more suitable for some designs.
Check the PSU installation socket in your cabinet and make your decision based on that. If there is a filter, you should point the fan towards the filter. But if there are no vents at the bottom, keep the fan facing toward the top.
Understand the external conditions and consider the temperature of the surrounding air. If you believe the interior of the PC case is comparatively cooler than the surrounding air, it is ideal to point the fan towards the top.

2. Are there any safety concerns with installing the PSU fan facing up or down?

Ans: There are almost no significant safety concerns with installing the PSU fan facing up or down as long as the installation is done correctly and the PSU is properly secured inside the case. However, there are a few things to keep in mind to ensure safe and reliable operation. First of all, check if the orientation of the PSU affects its grounding and power supply, which is much more important than a few degrees difference in the temperature level. Also, you need to be mindful of the internal cable management of the PSU which can be affected by its orientation.

3. Can the orientation of the PSU fan affect the stability of my system?

Ans: As we mentioned before, the orientation of the PSU fan can potentially affect the stability of your system. It usually happens if there is improper weight distribution of the components, and also if the case itself is not one of the heavy-duty options. Having a powerful and heavy PSU installed at the top of your case might make it very insatiable and you will have to be very careful with the case as it will be prone to tilting. Therefore, it is always preferred to keep the PSU at the bottom of the case, even if the fans are facing upwards.

Conclusion –

  • Today, we have discussed PSUs, their importance in a computer, and the necessity of PSU fans in detail. So, you must be familiar with all of this information by now and aware of the drastic changes observed in a system caused by minimal changes in the installation. In a lot of cases, users notice differences in the performance of the system just by choosing the right orientation of the PSU.
  • So, it is better to check out the best available installation option in your PC case and choose the right orientation of the PSU to maintain its performance. If you are still not sure, we will suggest going with the good-old trial-and-error method. You can keep the PSU facing downward for a couple of weeks, monitor the temperature levels in various scenarios, and then flip the unit for the next couple of weeks. This should give you enough information to decide which PSU orientation is perfect for your case.

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