Do You Install a Power Supply Up or Down?
When I was younger and computers were less customizable than they are now, you didn’t have a whole lot of choice on how a power supply was installed in a computer. Often times they already came installed in the case and were positioned at the top. These days, however, you have much more freedom on how you want to approach mounting your power supply. Especially now that they can be mounted on the bottom of a case.
This does beg the question though, do you install a power supply facing up or facing down? Generally you want to mount the power supply facing down if you have a shroud in your case and you are free to install it facing up if there is no shroud. PSUs are so efficient these days that you don’t need to worry about the heat of your system being impacted one way or another with how you mount your power supply. Therefor, you should mount your power supply in whatever way best suits the design of your case.
Power Supplies and Case Shrouds
Power supplies (known more commonly as PSUs) are what the name certainly implies. The power supply unit is the component of your system that supplies power to everything else inside the computer. It typically comes with a thick three prong plug that you jack into the electrical outlet in the wall. The power supply unit is a heavy-duty block of machinery that weighs a good amount as well.
Most PSUs will have two fans on them. One exhaust fan located where the power plug connects the power supply to the electrical outlet, and another fan that draws air into the PSU itself. These intake fans used to run all the time but over the years, the power supplies themselves have become so incredibly efficient that these intake fans rarely spin up and only do so when you put a heavy power load on the PSU.
Case design has also evolved to accommodate power supplies better in terms of aesthetics. These days, a lot of cases will come with a shroud that will helps isolate the power supply from the rest of the computer. This allows you to hide a lot of the excess length of the PSU wires and overall cleans up the look of the system itself.
Main Concerns of Mounting a Power Supply Face Down
As mentioned above, a lot of cases have shrouds to help hide the power supply cables. While this makes the inside of the case look much cleaner, it does present a problem of taking away some of your options when you’re installing your power supply.
There is typically very little clearance between the power supply and the walls of the shroud and so, it’s not advised to install the PSU where the intake fan is facing up. This will choke off the fan and in the case where it needs to spin up to help cool the PSU itself, it will have a hard time pulling in air and as a result, your power unit will run warmer.
Instead, you will have to install your power supply face down if your case has a shroud. Thankfully, all cases with shrouds will come with a grate along the bottom which will allow the intake fan to function facing down. The main concern with this however is that you cannot place the computer on a carpeted floor. The weight of the machine will cause it to sink into the carpet and choke off the fan. Avoid this problem by putting a solid piece of tile or wood under the system, or placing it up on a hard surface.
Another concern of installing your PSU face down is that because the intake and exhaust fans will be both facing out, they may create an air loop because of their proximity. There isn’t too much you can do about this, but making sure your computer is operating in an acceptable environment is never a bad idea to combat this.
A quick recap of these main concerns:
- Computer case shrouds prevent you from mounting your PSU face up because of airflow
- Installing your PSU face down prevents you from placing your computer on carpet
- If your power supply is installed face down make sure to place the computer on a smooth hard surface
- Ensure your computer isn’t operating in a hot environment to improve airflow to the power unit
Main Concerns of Mounting a Power Supply Face Up
If your computer case doesn’t have a shroud, then you’re free to install the power supply face up. This means the intake fan will be drawing air from the inside of your system and the exhaust will be expelling it out of the case itself. There are some concerns that should be taken into consideration if you plan to install your power unit this way however.
The main concern is whether or not you will be using water cooling (sometimes called liquid cooling) in your machine. Water cooling is a very efficient way to keep your components from heating up, however it comes with certain draw backs. Mainly, they have the possibility to developing a small drip or leak. If it does, gravity is going to take its course and water is going to drip into your power supply while it’s running. I don’t think I should have to say that this is extremely bad! If you intend to run your power supply facing up, I would recommend you do not water cool your system.
If you’re already running a lot of exhaust fans inside of your case, installing your PSU face up may not be the best option either. This can create negative air pressure and your system will begin drawing air in through the cracks and pulling in extra and unwanted dust. I cover this more in another article here.
Another concern worth mentioning is if you’re using an older power supply you want to avoid installing it face up. Older power units are not as efficient as modern ones and they will not be able to deal well with the warmer air that is typically present inside a computer.
A quick recap of these main concerns:
- If you’re using water cooling, a leak that occurs may drip water into your power supply if it’s face up
- Installing your PSU face up in a case with too many exhaust fans will cause negative air pressure
- Older power supplies won’t perform as well as a modern one if installed face up because of the system heat
Does it Matter Which Way You Install a Power Supply
Taking all the concerns posted above into account, you shouldn’t worry too much about which way you install your power supply. There are only a few situations that might force you to install your power supply one way or another, but over all, a little common sense will go a long way.
Overall with how amazing modern power supplies are with how they handle heat and power loads, you’re not going to find a lot of circumstances where you’re putting the PSU in much danger. Ensuring that it has an open space to draw in heat and isn’t getting water inside of it should be your two biggest concerns. After that, you won’t see a big performance difference one way or another.
Supplying the Juice (Conclusion)
Now that you know whether you should install a power supply up or down, and know more about the drawbacks of both options, you should be able to make a much more informed decision about how you want to approach this issue.
If you have any questions or comments about power supplies, shrouds, or what to do with them, don’t be afraid to leave a comment below. I’ll be sure to get back to you directly!