For the 3 top fans, can I have 2 of them as outtake and 1 of them as intake?

[PeacefulTech]

Hi guys,

I can put 3 fans at the top of my case. I will call them: rear, mid, and front fans. I currently have the rear and mid installed as outtake fans.

I am planning to install the front fan, which is the fan that is closest to the front of the case. This fan has no heat generating components below it. It is also right next to the front intake fan. As such, if I set this fan as an outtake fan, wouldn't that fan be sucking the fresh air from the front intake fan, and immediately push it out of the case?

As such, I am planning to have this top fan as an intake fan instead. However, people tend to not use top fan as intake fan. So I was wondering whether this is okay to do?

Further, the remaining 2 top fans are outtake fan. In other words, I have three fans in a row. Two of which are blowing air out while one of which is blowing air in. Would this be a problem? For example, would the intake and outtake fan interfere with each other since they are blowing air towards two different directions?

Thanks a lot.

P.S. here's a video of my build. It might be easier for me to explain with the visual:

 

[elghinnarisa]

It's a fan, you can do whatever you wish with them. There is no right or wrong, or something that will explode or implode. It will just be better or worse. Best way to figure that out is to test it with your current case and build. When I had my AIO i tried mounting it in many places with fans going in or out to figure out what worked best in terms of temperature and noise. I ended up keeping in in the front as a intake.

 

[PeacefulTech]

It's a fan, you can do whatever you wish with them. There is no right or wrong, or something that will explode or implode. It will just be better or worse. Best way to figure that out is to test it with your current case and build. When I had my AIO i tried mounting it in many places with fans going in or out to figure out what worked best in terms of temperature and noise. I ended up keeping in in the front as a intake.

Thanks for replying. I'm not really worried about my aio fans/radiator location. I'm planning to install a third case fan on the top of my case, and I'm wondering whether having it as an intake fan would be problematic given: 1. it's a top fan and 2. two of my top fans are already outtake fans

 

[elghinnarisa]

I know, I was giving an example if you re-read it again.

 

[joemama]

I'm expecting the airflow to be a mess, otherwise no problems with that. You could really just test it yourself as it isn't something hard.

 

[64K]

Youve got 3 intake fans on the front. I would just make the 3 top fans outtake fans. It seems to me if you put 1 intake fan on the top the 2 outtake fans would just pull the air from that intake fan right out and it wouldn't do much good.

 

[PeacefulTech]

Youve got 3 intake fans on the front. I would just make the 3 top fans outtake fans. It seems to me if you put 1 intake fan on the top the 2 outtake fans would just pull the air from that intake fan right out and it wouldn't do much good.

Ya that makes sense. The top fan that I will install will be right next to the front intake fans though. Wouldn't it be pulling the front intake fan's fresh air right out of the case?

 

[claes]

There’s a chance it’ll recirculate the hot air blowing out from the middle-top fan. As @64K noted and you pointed out, you’re not actually cooling anything with an intake there.

Do you need another fan? Are any of your components running hotter than you’d like?

If it were me, I’d mount the radiator to the top and run all top fans as exhaust, whether it’s two or three. This way your GPU should run a little cooler as it won’t be taking in the radiator’s heat.

Or, if mounting the radiator on front is preferred, I’d actually just run the front and top as intakes. Hopefully that setup would create a cooler case temperature and thus cooler air for the GPU to work with.

edit: IMHO, that’s too many fans for such a small chassis.

 

[64K]

Ya that makes sense. The top fan that I will install will be right next to the front intake fans though. Wouldn't it be pulling the front intake fan's fresh air right out of the case?

Do you have any cutouts on the bottom of the case? If so you could move the intake fans to the bottom of the case.

 

[PeacefulTech]

There’s a chance it’ll recirculate the hot air blowing out from the middle-top fan. As @64K noted and you pointed out, you’re not actually cooling anything with an intake there.

Do you need another fan? Are any of your components running hotter than you’d like?

If it were me, I’d mount the radiator to the top and run all top fans as exhaust, whether it’s two or three. This way your GPU should run a little cooler as it won’t be taking in the radiator’s heat.

Or, if mounting the radiator on front is preferred, I’d actually just run the front and top as intakes. Hopefully that setup would create a cooler case temperature and thus cooler air for the GPU to work with.

edit: IMHO, that’s too many fans for such a small chassis.

Oh this is interesting. So if I were to keep the radiator at the front, your suggestion is to have the top three fans and front three radiator fans as intakes? This would mean 6 intake fans and 1 outtake fans (at the back). Is that what you meant?

Do you have any cutouts on the bottom of the case? If so you could move the intake fans to the bottom of the case.

Unfortunately the max number of fans for my case is 7, with 3 at the front, 3 on top, and one at the back

 

[mtcn77]

If you do that you will turn your case into a vacuum cleaner. You prioritise intake for this reason - so that air doesn't slip in through the cutouts.

 

[PeacefulTech]

If you do that you will turn your case into a vacuum cleaner. You prioritise intake for this reason - so that air doesn't slip in through the cutouts.

Ya I agree. Positive air pressure inside the case is optimal. Would you suggest I use the top fan as intake then? (Front 3 are already intake. Back 1 is outtake. So I only have top 3 to work with. There aren’t any other outputs in the case)

 

[claes]

If you’re trying to fill all of the slots, all intake except rear exhaust is probably your best choice if the radiator is in front.

Still, that’s a silly amount of fans IMO. Is there a problem component that’s overheating?

 

[mtcn77]

Ya I agree. Positive air pressure inside the case is optimal. Would you suggest I use the top fan as intake then? (Front 3 are already intake. Back 1 is outtake. So I only have top 3 to work with. There aren’t any other outputs in the case)

You know what, switch the direction of every fan. Front - exhaust, rear - intake.
You are running liquid cooling, it would be best for your radiator fans to take the cooler case air than let the hub heat up and there is no other cooling alternative for your vrms. Vrms have to have fresh, cool air.

 

[AusWolf]

You can, but it doesn't mean you should. Heat naturally rises, so with an intake on the top, you're only obstructing its way. Besides, an intake fan right next to an exhaust has a chance of pulling already exhausted hot air back into the case. Not recommended.

 

[mtcn77]

You can, but it doesn't mean you should. Heat naturally rises, so with an intake on the top, you're only obstructing its way.

That is liquid cooling, nothing is rising there. The heat is at the front radiator.

 

[AusWolf]

That is liquid cooling, nothing is rising there. The heat is at the front radiator.

Sorry, my bad. In that case, I'd suggest installing the radiator on the top, and using its fans as exhaust in order to trap as little hot air inside the case as possible.

Also, an intake fan on the top, right next to a front radiator that also acts as intake is counterproductive in removing heat from the radiator. The top should be exhaust in any case.

 

[mtcn77]

In that case, I'd suggest installing the radiator on the top, and using its fans as exhaust in order to trap as little hot air inside the case as possible.

I agree, no reason to restrict the air intake. While it could still work, cool air has higher impedance. Good radiator fans are not available to everyone. It would be easier to push it through the radiator in heated state and with the fans out of the way of the hot radiator stream.