# Case fan exhaust or intake?



## mihalyk2000 (Aug 2, 2018)

So I have a pretty basic case, with only 1 fan. CPU fan is normal, stock, above od that there is the PSU fan exhausting all the air(even from the CPU) and right now I have a case fan at the back(cpu intake from side part, psu exhaust from cpu, so FROM INSIDE, NO PSU FAN OUTSIDE) side exhausting the air from cpu and psu too(basically no intake fan). Should I change that fan to give air for the cpu/psu/case? Right now, it exhaust pretty hot air after long gaming periods. CPU has a direct "route", like a tunnel, almost from cooler to case side, so it's taking air from outside-ish (bcs it's maybe from 2-5 cm the tunnel from the cooler)


----------



## dirtyferret (Aug 2, 2018)

This sounds like one of those DELL/HP cases from ten years back that had the CPU exhaust tunnel leading to the side panel.  

You want the rear fan as an outake (pushing the hot air out of the case).  Look into the getting another fan for the front of the case as an intake.


----------



## natr0n (Aug 2, 2018)

Do it the right way. Pry the case open and point a house fan in there.


----------



## nomdeplume (Aug 2, 2018)

Electric cooling pad behind mb and 200mm case fan mounted in panel opposite it.  If dust gets to be a problem before the chassis frame explodes.  Just toss a colander over the fan and let the pressure hold it there.  

Document entire process and post to ghetto mods thread.


----------



## peche (Aug 2, 2018)

Are you able to post a pic of the case?
Also fill this! will help others to help!


----------



## mihalyk2000 (Aug 3, 2018)

peche said:


> Are you able to post a pic of the case?
> Also fill this! will help others to help!


Also, i filled that link. This is how it's showing inside, and it's not a HP/Dell case.


----------



## eidairaman1 (Aug 3, 2018)

ATX form, rear is exhaust, top is exhaust, front is intake, bottom is intake.


----------



## Caring1 (Aug 3, 2018)

Remove the plastic tunnel from the side panel of the case and install a fan there, one or two screws should be enough to hold it in place, just remember it's there when you open the panel so you don't rip the wire off.
I've done that on a similar case and it worked great.


----------



## Athlonite (Aug 3, 2018)

any chance we can get a full shot of the case from the side that one you posted really isn't conducive to seeing whats what in relation to everything


----------



## RejZoR (Aug 3, 2018)

If that's the only fan, and PSU is sucking enough air out, flip it over so you're supplying cold air into cpu and PSU will pump out the hot air. I've used PSU this way before in a miniATX build I had. Worked pretty well, but PSU fan shouldn't be a very slow one. It won't exhaust enough heat...


----------



## peche (Aug 3, 2018)

mihalyk2000 said:


> Also, i filled that link. This is how it's showing inside, and it's not a HP/Dell case.
> View attachment 104820


i mean a pic that shows completely your case lad, 



eidairaman1 said:


> ATX form, rear is exhaust, top is exhaust, front is intake, bottom is intake.


the atx form you describe is a comon fan setup, im afraid my friend that this partucular case might need a ghetto solution, 


Athlonite said:


> any chance we can get a full shot of the case from the side that one you posted really isn't conducive to seeing whats what in relation to everything


+1



RejZoR said:


> If that's the only fan, and PSU is sucking enough air out, flip it over so you're supplying cold air into cpu and PSU will pump out the hot air. I've used PSU this way before in a miniATX build I had. Worked pretty well, but PSU fan shouldn't be a very slow one. It won't exhaust enough heat...


you are right, older and generic cases might work this way, but is not good for PSU life, they might last or endure this situation, but if you apply a little logic, is not good idea,


----------



## TheoneandonlyMrK (Aug 3, 2018)

Do as i did , fit a 200mm intake fan onto the removable side panel , then be sure to clean it out regularly since the inner fluff ratio will go up exponentially or,
Buy a new case(as i also did after a year of the above) and transfer your gear into a case made to actually keep stuff relatively cool.


----------



## mihalyk2000 (Aug 3, 2018)

RejZoR said:


> If that's the only fan, and PSU is sucking enough air out, flip it over so you're supplying cold air into cpu and PSU will pump out the hot air. I've used PSU this way before in a miniATX build I had. Worked pretty well, but PSU fan shouldn't be a very slow one. It won't exhaust enough heat...



Thanks, this is what I wanted to hear, hopefully it will be better.


----------



## RejZoR (Aug 3, 2018)

@peche 
It's not like he has whole lot of options. PSU will suck in hot air no matter what. It's just a matter of few degrees. If cold air is mixing with the hot of CPU cooler, the end temp might be about the same with CPU temp being lower. Opposed to sucking all air out and trying to get it in through tiny gaps in the case...


----------



## TheoneandonlyMrK (Aug 3, 2018)

mihalyk2000 said:


> Thanks, this is what I wanted to hear, hopefully it will be better.


Except it's illogical ,if you reverse the rear fan it will feed in more air, to the psu, the cpu fan wont disperse the cooler air enough and laminar flow will create a small loop in and out, your psu will benefit ,the system wont ,but to be fair it won't hurt too much to try.
Good luck hopefully im wrong.


----------



## RejZoR (Aug 3, 2018)

It will help. The loop will circulate past the CPU cooler. On case exterior, hot air will be rising, cold air going into the case will come from lower part. They won't mix much.


----------



## peche (Aug 3, 2018)

RejZoR said:


> @peche
> It's not like he has whole lot of options. PSU will suck in hot air no matter what. It's just a matter of few degrees. If cold air is mixing with the hot of CPU cooler, the end temp might be about the same with CPU temp being lower. Opposed to sucking all air out and trying to get it in through tiny gaps in the case...



totally agreed, wont destroy PSU today or tomorrow, but is not the best thing to do, also, a better airflow via mod or customization will be another upgrade that could bring better temps, for example using zipties to add a fan on the 5.25" drives bay or cage, also cutting or making place for new fans, my previous comment was just a single opinion,



theoneandonlymrk said:


> Except it's illogical ,if you reverse the rear fan it will feed in more air, to the psu, the cpu fan wont disperse the cooler air enough and laminar flow will create a small loop in and out, your psu will benefit ,the system wont ,but to be fair it won't hurt too much to try.
> Good luck hopefully im wrong.



no sense, if you reverse the rear fan to intake, there will be a gap of cold and hot air, all cases need a exhaust fan to take heat out the case, if the case were having the enough spots for adding fans reverse setup could be used, but this case have fan position problems, a better idea will be the most economic or budgetish case around, for example $30 cm or TT low end ones, or older, ebay have several decent cases for a budget build under $30 even, also used is another great option, cases are rarely worn or damaged, might be scratched or worn paint, but the thing is to enhance cooling,


----------



## RejZoR (Aug 3, 2018)

Granted, I had Corsair HX750 which is rated at much higher temperatures so I didn't really care if it was pumping out heat. I think it was rated at 75°C where most cheap ones are at 45-50°C. I had Core i7 920. I doubt this system has such powerhouse...


----------



## TheoneandonlyMrK (Aug 3, 2018)

peche said:


> totally agreed, wont destroy PSU today or tomorrow, but is not the best thing to do, also, a better airflow via mod or customization will be another upgrade that could bring better temps, for example using zipties to add a fan on the 5.25" drives bay or cage, also cutting or making place for new fans, my previous comment was just a single opinion,
> 
> 
> 
> no sense, if you reverse the rear fan to intake, there will be a gap of cold and hot air, all cases need a exhaust fan to take heat out the case, if the case were having the enough spots for adding fans reverse setup could be used, but this case have fan position problems, a better idea will be the most economic or budgetish case around, for example $30 cm or TT low end ones, or older, ebay have several decent cases for a budget build under $30 even, also used is another great option, cases are rarely worn or damaged, might be scratched or worn paint, but the thing is to enhance cooling,


Wrong end of stick me thinks.
I agree with you ,get a new case ,polishing a turd just gets your hands messy and takes up valuable time , it doesn't make a rose either.

I was trying to describe the fact that laminar flow will starve the case of fresh air imho ie in the back , straight to the psu then out of the case.


----------



## peche (Aug 3, 2018)

theoneandonlymrk said:


> Wrong end of stick me thinks.
> I agree with you ,get a new case ,polishing a turd just gets your hands messy and takes up valuable time , it doesn't make a rose either.
> 
> I was trying to describe the fact that laminar flow will starve the case of fresh air imho ie in the back , straight to the psu then out of the case.


totally understood, i have done, repaired and also modded several cheap cases for better cooling and also trying to get a decent looking despite the custom cuts and so, at the end, the user is the one that know the final goal!


----------



## mihalyk2000 (Aug 3, 2018)

RejZoR said:


> Granted, I had Corsair HX750 which is rated at much higher temperatures so I didn't really care if it was pumping out heat. I think it was rated at 75°C where most cheap ones are at 45-50°C. I had Core i7 920. I doubt this system has such powerhouse...



Well, I tried it, almost died. GPU was at 100C after just 5 mins. Reversed back, went normally to 70-80C. I already had a custom fan curve on GPU, but I guess I set one for the CPU too. SpeedFan not working, so I can't modify the case fan sadly. I never changed the thermal paste on the CPU/GPU, maybe will try that in some days. Thanks everyone, hopefully this will help others too.
(why so hot ? i'm heavily underclocking both GPU/CPU (gpu at maximum voltage/+20 power limit, +42+% core clock OC xd, also CPU on stock cooler from 3.5GHz to 4.2)
Everything is stable, but you know, summer is here, and I don't want exactly to feel that hot in my room.


----------



## John Naylor (Aug 3, 2018)

Any chance a new case is in the cards ?  A pair of added 140mm fans in front would solve most builds issues.  Newegg has the PH-140SP's for $10 every 6 weeks or so.

https://www.newegg.com/Product/Product.aspx?Item=N82E16811854071

1 fan or 16 fans,  the room temperatre is not going to change. If ya system is consuming 450 watts, then 450 watts of heat is entering the room no matter how many fans are moving it there.

A summer solution that would work is to put a desk fan in place blowing air into the case w/ side panel removed.


----------



## mihalyk2000 (Aug 3, 2018)

John Naylor said:


> Any chance a new case is in the cards ?  A pair of added 140mm fans in front would solve most builds issues.  Newegg has the PH-140SP's for $10 every 6 weeks or so.
> 
> https://www.newegg.com/Product/Product.aspx?Item=N82E16811854071
> 
> ...


 Thanks, but i won't bother anymore. I'm going to college and I'll just buy a ryzen/rx laptop, and sell this PC for a friend. Maybe I'll apply a new thermal paste for cpu/gpu but that's it.


----------



## RejZoR (Aug 3, 2018)

It's hard to say what's what without full look at the case. The image you provided only shows us as much...


----------



## mihalyk2000 (Aug 4, 2018)

RejZoR said:


> It's hard to say what's what without full look at the case. The image you provided only shows us as much...



No problem  at least i got some opinions!


----------



## RejZoR (Aug 4, 2018)

Are you sure there are no fan mounting points in the front? Not even for a crappy little 80mm ? I've had ancient steel cases from 20 years ago that had at least 80mm in the front or at worst, at least intake grill even if without fan.


----------



## Vlada011 (Aug 4, 2018)

I always try to install case fans in exhaust configuration.
But sometimes could be problem. Fans on radiators give better performance in pushing air throught radiator than pull only.
And maybe is mistake, but my priority is, if we talk about radiator fans to push air thorugh radiator and than if it's possible as exhaust.
If not intake rather than pull exhaust. 
That's my opinion and maybe is wrong.


----------

