[SOLVED] Computer fans, suck or blow?

[Marplot]

I understand that it is usual that fans are set to blow up the top of the case - hot air rises - and the front fans suck in. Makes sense. ATX Tower case. Fans in the front and three more on the top. There is also a 140mm exhaust fan.

However, my Lian Li AIO Galahad 360mm shows the fans have a logo on the "suck side" therefore it is set to blow through the radiator pulling the inside, hot air, and blowing it outside. Click here if needed Lian Cooler

Logically I should be sucking in the cooler outside air. Also, my case filters are on the outside of the case, this would indicate the outside air should be sucked through the filters, filtering the dust from coming in.

So, should I mount the cooler fans in reverse configuration? This way they blow into the case, sucking in the cooler outside air and it is being filtered.

 

[ZenSunnyDuck]

Well what I did was put my cpu cooler in the front and replaced the front fans. Dont take off the fans just mount the backplate of the cooler to the fans. This should work fine. Just put the fans that come with the cpu cooler and use them as exhaust fans on the top of ur case

 

[hotaru.hino]

While logic dictates that hot air rises due to physics, natural convection contributes very little when the parts are cooled via a fan.

If you really want to know what's better, the only way to do so is to try one configuration, then the other. Run something like CineBench R23 and see what the temperature looks like over time

 

[Karadjgne]

Fans depend on placement as well as orientation. If the fan is at the front of the case and the radiator is behind it, then the fan is considered as in Push, blow. If you move the fan behind the radiator without flipping it around, it's still an intake but is considered in Pull orientation, suck.

So throwing out actual nomenclature, the fans at intake need to move air Into the case, the fans at exhaust need to move air Out of the case.

Intake low-front, exhaust high-rear.

As far as where to put the rad, that's not only a personal thing due to aesthetics, but also a fitment thing. Some cases are built very short, the motherboard sits very close to the top of the case. While this leaves ample room for a 25mm fan, it often does not leave much room for a 30mm radiator And the 25mm thick fans. Front mount can have issues with the extremely long gpus, depending on how deep the case is. Newer designs are moving to a shallower design since that giant airspace where 6-9 hdd trays used to sit is no longer there. That cuts down on manufacture costs, less material, smaller glass panels etc.

Don't over think the temps. If the gpu generally runs hotter than the cpu, top mount rad can balance that out some, means cooler air directly to the gpu even if the cpu suffers a little. If the gpu usually doesn't run as hot as the cpu, front mount is preferable, the cpu radiator getting the lions share of cooler air. But the temps won't vary much, usually @ 5°C ±.

 

[Marplot]

I turned my fans, mounted to the radiator, around to pull the cooler outside inside my case. Mounted three more fans on the inside top of the case to exhaust as well as a 140mm fan exhausting through the rear.

 

[tennis2]

However, my Lian Li AIO Galahad 360mm shows the fans have a logo on the "suck side" therefore it is set to blow through the radiator pulling the inside, hot air, and blowing it outside.

All fans are laid out in the same fashion. The spokes that hold the motor/hub in place are on the downstream side. The logo (if there is one) would be on the upstream side) In the photo you linked, the fans would be properly set up for a top-mounted rad blowing air out the case. This is also the most convenient way to photograph an AIO.

therefore it is set to blow through the radiator pulling the inside, hot air, and blowing it outside.

You can mount the fans to either side of the rad and as push or pull (depending on which side of the fan is touching the rad). The fans aren't attached to the rad when you open the box.

 

[rickypicky5]

In general,

Suck in the front, blow out the top and back.

 

[Marplot]

Thank you for your input. It seems to me that the cooler/outside the case should be pulled through the rad. So I set mine on the front of my case with the "spokes" on the inside of the case to pull the outside air into the case. I then put the other three fans to pull the inside/heat and exhaust through the top of the case. Seems to be working fine.

Regardless of whether the fans are located on either side of the rad they will pull or push unless they are flopped. Notice in my picture that the rad, on the right side are showing the spokes. In testing the CPU was cooler with my arrangement.

Rad pulling cooler air into the case

 

[Marplot]

However, I bought an Alienware Aurora R13, new, about 30 days ago. It is set up where the rad fan does suck from inside the case. I am perplexed. From an engineering perspective, the fan should pull outside cooler air into the case. BUT the gu7ys at Dell should really know their stuff.

WTF it seems that whatever way you like.

 

[tennis2]

Alienware Aurora R13 set up where the rad fan does suck from inside the case.

My rear-mounted 120mm AIO is also an exhaust. Rear exhaust is a common place to mount a 120mm AIO. It's not illegal to do that. You just know that your AIO fan(s) are sucking/pushing pre-heated air from the GPU exhaust across the rad. Slightly higher CPU temps, sure. On the flip side, if your AIO is intake, then your GPU is getting pre-heated air, so GPU temps would be higher.

I have a Ryzen 5600G that barely draws 60W under full load and a 3060Ti that has a stock TDP of 240W. Since my 120mm AIO is more than enough to keep the CPU cool, I prioritize the cool/fresh air intake to keep the GPU temps/noise as low as possible.

BUT the gu7ys at Dell should really know their stuff.

Ehhhh. Don't give them more credit than they deserve. One thing is for sure, Dell/HP/Lenovo/etc aggressively strive to minimize case fans. In fact, they do a LOT of custom/creative/strange/idiotic things to save a nickel here and there.
I doubt you'll find anything more than a 120mm AIO in an OEM pre-built. If the AIO is an optional add-on, then the system probably/hopefully would just have a 120mm exhaust fan there in the base config.

 

[Karadjgne]

BUT the gu7ys at Dell should really know their stuff.

Haha. No. Nice but wishful thinking. My old Dell 8400 had a single 92mm fan. Just one. Stuck on top of the cpu heatsink in Pull, the exhaust of which was channeled by a plastic shroud to the outside where the rear exhaust fan would normally be located. Fan pulled air in through the heatsink then blew it through that plastic hose to the outside. Talk about cheap. And because of the design of the case, even being a bigger ATX Mid Tower, there was Zero space for even a 120mm exhaust fan, so a blower style gpu had to be used.

And the cpu was a P4 3.4GHz, with a chinzy small heatsink and 92mm fan. First time I ran Prime95, it laughed at me and shutdown 10 seconds later.

Common belief by many is that Dell spends more time and wastes more money trying Not to do things right, than they would if they just did it right to start with.

 

[tennis2]

Common belief by many is that Dell spends more time and wastes more money trying Not to do things right, than they would if they just did it right to start with.

For sure! Oftentimes it's hard to fathom how economy of scale justifies the design/validation/tooling/fab that they incur on themselves just to make their PCs as barebones as possible. I get needing/wanting to aesthetically differentiate your systems from your competitors, but they rarely stop with just the exterior case design.

 

[Marplot]

My Alienware Aurora R13 is working great! Had some great reviews. I am keeping it. Plays very well with games. Makes a cool statement in my home theater setup.

 

[Mr.Random]

yeah my aio water cooler had the fans blowing hot air from the inside of my rig. changed them to push cold air from outside in and it made a difference. also switched everything else in the case to vent out.