PSU fan direction question

[aLcATRAZ]

Hey fellas

I'm back to building desktops again after a looong break. Saw something in my new build today that surprised me.

My whole life I've only ever seen PSU fans blowing air out the back of the chassi. Today I noticed that my FSP 1U unit actually pulls air in from the back, and then blows it into the case. It's not a big deal because it's a fairly open case and the build is fairly low power.

I've never seen PSUs exhausting hot air into the case before. I'm considering opening it up and flipping it.

Any thoughts? (It's a modular FSP300-60FAG 80plus Gold)

 

[pitingres]

Most ATX power supplies have an intake fan on bottom or top, and most cases seem to encourage fan on the bottom. Exhaust will generally be out the back. No idea what rack PSU's do; maybe the assumption is that the case air is already hot and the PSU wants outside cool air?

 

[mtrupi]

I looked at a couple 1u chassis built with this and it looked to me the fan faces the front toward the user. This would explain why the the PSU fan is reverse from what you expected. Should you flip it depends on your specific build.

 

[GiGaBiTe]

In some server designs, the power supply is mounted in the front of the case, installed backwards. With the fan being reversed, the PSU would be following the normal airflow of the server by taking in air from the front of the case and helping blow it out the back.

Though, there are also certain instances where blowing inside the case is beneficial, but not standard. One example was Dell's horrible Optiplex GX2x0 SFF cases. These had zero airflow into the case and a smokin' hot P4. The PSU would get so hot that it would shut down on high temp. I would reverse the fans on these units to let the PSU get cold air in, which would keep them cool enough to not shut off.

 

[pendragon1]

thats normal and 1U is not "desktop"

 

[aLcATRAZ]

Thanks for the replies. I really appreciate them.

thats normal and 1U is not "desktop"

It's a very quiet modular psu with a graphics card power lead. So I'm pretty sure they're expanding on what some people think 1U are supposed to be for. I'm using it in a small form factor "gaming" chassi. (Although I don't game.)

I looked at a couple 1u chassis built with this and it looked to me the fan faces the front toward the user. This would explain why the the PSU fan is reverse from what you expected. Should you flip it depends on your specific build.

It's also got the power lead socket next to the fan so I'm pretty sure it's meant to be installed in the back. That's what's so odd.

 

[aLcATRAZ]

This is what it looks like if anyone's wondering.