PSU for cases without bottom vents

[ojas]

i've been noticing that some antec cases that i've had my eyes on like the three hundred or dark fleet series have bottom mounted PSU's but dont have a bottom exhaust for them. Most PSUs that are 550W and above have top exhaust fans now. That creates a problem, so far as i can see, because if you install it in the case the right way up, you end up blowing hot air into the case, and if you install it upside down, air cant escape.

can anyone suggest a solution to this problem? or suggest a 600W+ PSU with it's exhaust pointing backward?

thanks...

 

[Randomacts]

The top is intake... unless I am missing something here.

 

[obsidian86]

all psu's draw air in through the fan and exhaust out the back

 

[Randomacts]

all psu's draw air in through the fan and exhaust out the back

That is what I thought..


Isn't that a reason why PSUs where moved to the bottom? So it could have cold air to intake?

 

[obsidian86]

partly,but top or bottom doesn really matter the biggest aspect is the quality of the psu and how it deals with the heat a good psu rated continues output at 50c will be fine either way campared to a psu rated at 25c or 35c

 

[RetiredChief]

agree with obsidian86 on quality.

Placement does have an effect on air currents inside the case.
Top mounted
Intially (older) cases had no top mounted fans, heat rises and the PSU fan helped airflow.
Generally improves air flow across cpu, chipsets, memory and VRs. But on the neg side, the air intack was higher temp therfore less cooling inside PSU.
In one of my cases (place for top/bottom mounting) No top fan the temp of my chipset increased by about 4 C when moving from top to bottom.
However, this advantage was elieminated with the cases with large top mounted fans.
Bottom mount.
Best, if have top mounted case fan, or high volume rear fan..
With fan on bottom the air intack is ambient air and therefore inside of PSU is cooler, always a plus, even for quality PSUs.
With top mounted fans, many cases allow for "upside down" placement of PSU.
For bottom mounted case with NO air intake holes - a drill and a 3/16 in drill bit does wonders.

 

[jb6684]

All power supplies intake air via a small fan at the back or a big fan on the bottom....

All power supplies then vent that air out the back of the case...... (there is no such thing as a power supply that blows any hot air into the case)


If you have a case with a bottom mounted PS, and, no direct opening to out side fresh air...
- you can find a big power supply with front to back air flow like this one:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=antec+tpq&x=0&y=0


- or mount this type of power supply big fan down, most have rails that lift the power supply a 1/4 to 1/2 inch off the case floor to allow air intake
- or mount this type with big fan Up to allow a bit more open space to draw air from
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=antec+tp&x=0&y=0

 

[ojas]

i see...i got really confused because the manufacturers aren't clear on which fans do what, they just keep advertising that there are a hundred fans on this supply, bla, bla, bla...
plus i tried looking at the pictures, and all i saw in most PSU's was one big fan on top and just a grill to the rear, so that led me to believe that the big fan was a exhaust fan.
my present PSU is a 400W top mounted one, with one fan at the back and a vent facing inside the case for intake, so that couldn't help my understanding either.
And i needed a 550W replacement for that too...

but alright, if the top fan's an intake fan, then that solves a lot of my worries and explains some things too (like the thermaltake armor a60 having a bottom dust filter for the PSU fan)...

thanks all...

 

[jb6684]

Reminder: select a best answer so the thread can be marked as "Solved" and closed out.....

 

[ojas]

Best answer selected by ojas.

 

[ojas]

though i may want to add, i put the same question to corsair, they say, that at least in the case of the VX550, that top fan is an exhaust fan.

what the heck.

 

[jb6684]

Sure it's an exhaust fan, From the perspective of the power supply itself that is true.

BUT, that fan still Pulls air INTO the power supply, and blows it OUT the back of the power supply thru the mesh panel that contains the power switch and receptacle for the power cord.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139004


I own the Corsair TX650, TX750, and HX850 they work this way...

I also seen a lot of power supplies, from a variety of companies, they all work this way.

 

[ojas]

yup you're right, hands down!...the corsair 'power guy' (steve lee) rephrased his reply to something that was very similar to what you're saying...
thanks jb6648...