Bottom mounted psu

[valo123]

I recently purchased an antec 900
http://www.newegg.com/Product/...x?Item=N82E16811129021
and a thermaltake 550w psu
http://www.newegg.com/Product/...x?Item=N82E16817153051

I'm sure this question has been asked before but I want advice for this specific case. The case has a bottom mounting for the psu, should I aim the intake fan up or down? I'm not quite sure if there will be space between the psu and the bottom of the case.

Maybe someone with this specific case can tell me what they did for best circulation?
Thanks in advance :thumbsup:

 

[Thund3rb1rd]

I have a CM 690
it has a bottom mount PSU, and I pointed the exhaust down
but, the case also has a spot for a 120mm in front of the psu, I blocked this off so psu exhaust isn't hauled back into the case
my cpu load temp has never gone over 58C
gpu never over 80C

 

[SparkyJJO]

PSU will only go in that 900 one way. With the fan up. If you put it down it won't screw in and even if it did there would be no airflow to the PSU and bye-bye PSU.

 

[valo123]

So if I mount it with the fan up the exhaust will go out the back of the case correct?

 

[Zepper]

The 900's PSU mount is bi-directional. Generally there will be venting in the bottom of the case if the fan is supposed to go that way. So I hope you don't have an Enermax Liberty as their fans aren't too happy facing upward. IOW, fan facing upwards is default for the 900 unless you have an old-school PSU like the Earthwatts boxes which are straight-thru airflow and lack side mounted 120mm or larger frans.

.bh.

 

[CDC Mail Guy]

Originally posted by: Zepper
The 900's PSU mound is bi-directional.

QFT. I just got my 900 case today, and it specifically states in the instruction booklet (yes, I READ it ) that the PSU can be mounted either way.

 

[SilentRunning]

Originally posted by: Thund3rb1rd
I have a CM 690
it has a bottom mount PSU, and I pointed the exhaust down
but, the case also has a spot for a 120mm in front of the psu, I blocked this off so psu exhaust isn't hauled back into the case
my cpu load temp has never gone over 58C
gpu never over 80C

The power supply should be exhausting out the rear and intaking through the bottom. If your power supply fan is exhausting out the 120mm bottom hole then someone at the factory installed the power supply's fan backwards.

 

[Zepper]

Yes, in the 690 and 900 (as well as the great majority of other cases) the exhaust from the PSU will be out the rear.

.bh.

 

[imported_Scoop]

Unless you're into modding and dremel a hole for the intake at the bottom, you need to face it upwards to take air from inside the case.

 

[CDC Mail Guy]

Originally posted by: Scoop
Unless you're into modding and dremel a hole for the intake at the bottom, you need to face it upwards to take air from inside the case.

Which wouldn't be that bad of an idea would it? I mean, instead of giving the psu warm air from inside the case, you would be giving it fresh/cool air correct? After all, there's "PLANTY" of exhaust in the Antec900 case!

 

[imported_Scoop]

Originally posted by: CDC Mail Guy

Originally posted by: Scoop
Unless you're into modding and dremel a hole for the intake at the bottom, you need to face it upwards to take air from inside the case.

Which wouldn't be that bad of an idea would it? I mean, instead of giving the psu warm air from inside the case, you would be giving it fresh/cool air correct? After all, there's "PLANTY" of exhaust in the Antec900 case!

Yeah exactly, if I'd have that good skills cutting metal I'd do it. Instead I bought a CM690 which has a grill under the PSU on the bottom Though I'm thinking that I should cut it off too and give the same treatment to all the other unnecessary grills spoiling the airflow and causing noise in the fanslots. Something like this would be awesome:

http://img.photobucket.com/alb.../alex0989/P1010320.jpg
http://img.photobucket.com/alb.../alex0989/P1010319.jpg

 

[MadScientist]

I'm quoting from my Antec 900's manual:
"Power supplies with fans on the bottom of the power supply will need to be mounted so that the fan is facing the top of the case."
But then it states in the same paragraph:
"Nine Hundred provides mounting holes for power supplies with standard mounting layouts to be installed upside up or upside down."
When my Corsair 620W is installed in my 900, upside down, fan side up, the top of the psu sits directly on the bottom of the case. I would have to cut a hole in the bottom, as Scoop stated, to mount it fan side down for get air flow to the PSU, but the 2 rubber supports would have to be moved, and even then you would only have ~1/4" space under the case, unless you replaced the stock feet with higher ones, to bring in air.
And why even bother, as CDC Mail Guy has already stated, this case provides excellent airflow, even with the fans on their low settings.

 

[Zepper]

Has CM changed the 690? Mine has a plastic front fan holder w/ an integrated nylon filter, not a metal fan housing as shown in the first pic...

.bh.

 

[imported_Scoop]

Zepper: it's modded.

 

[Zepper]

Well, it's easier to mod plastic than steel, so why dig thru the parts box for a metal fan bracket to mod?

.bh.

 

[imported_Scoop]

Originally posted by: Zepper
Well, it's easier to mod plastic than steel, so why dig thru the parts box for a metal fan bracket to mod?

.bh.

I'm not sure I follow you... Here's what the front originally looks like without the panel

http://i55.photobucket.com/alb...r%20CM690/6cc3e5de.jpg

 

[valo123]

Yeah, I'll mount it with the intake fan facing upwards. Hopefully it draws out some of the heat the BFG 8800gt is producing.

I think I might mod the case in order to place a fan behind the mobo...has anyone tried this yet?

 

[Zepper]

Here's my 690's front fan mounting:
http://i52.photobucket.com/alb...C690FrontFanHolder.jpg

So they did change from metal to plastic with a nylon net integrated filter.

.bh.

 

[tsponholz]

As you are probably getting from other posts, the ideal would be to have the intake facing down and have intake vents directly beneath it. This way the PSU is drawing in it's own fresh/cool air and then pumping it out the back -- keeping it totally independant of the rest of the case.

Most new cases with bottom mount PSU have an intake directly below the PSU, and some even have nice seales to completely isolate the airflow (the CoolerMaster Cosmos has a really nice set up for this.) Even my older designed case (though brand new to me) Lian-Li pc-v1000 is set up this way, though not as "isolated' as the new CoolerMasters.

My advice (for what it is worth) if the 900 doesn't have a bottom air intake for your PSU, make one. Of course this also means the case can't sit flush on the floor, or even really close to. It needs to have feet or a mount that keeps it high enough off the floor to draw plenty of air in.

 

[valo123]

I was thinking about using the psu to draw the heat out of the case (gpu heat). But you think it's a better idea to just have the psu cool itself? I think if the psu cooling system was designed to act independently it would have been designed differently, along with most cases.

 

[imported_Scoop]

Originally posted by: Zepper
Here's my 690's front fan mounting:
http://i52.photobucket.com/alb...C690FrontFanHolder.jpg

So they did change from metal to plastic with a nylon net integrated filter.

.bh.

You're right! I hadn't taken the front panel off from my case yet but I just did and I have that black plastic thing also! BTW, taking the front panel off was kind of scary, I thought I was gonna break it for sure.

 

[imported_Scoop]

Originally posted by: valo123
I was thinking about using the psu to draw the heat out of the case (gpu heat). But you think it's a better idea to just have the psu cool itself? I think if the psu cooling system was designed to act independently it would have been designed differently, along with most cases.

The PSU should get cool air to keep itself cool, it's not ideal for it to draw hot air inside.

 

[tsponholz]

Originally posted by: valo123
But you think it's a better idea to just have the psu cool itself? I think if the psu cooling system was designed to act independently it would have been designed differently, along with most cases.

The PSU will obviouly work ok bringing in hot air from inside the case, but it keeps everything cooler if it can draw "fresh" air. The PSU will stay cooler, and therefore not be as hot sitting inside your case heating up everything else close by.

If you have adequate airflow without using the PSU fan to move air insde the case (and the the 900 should with it's other fans) you don't need to use it to exhaust the hot air. Plus, a general rule of thumb for "good" airflow paterns inside a case is to bring cool air in from the bottom (or low) and exhaust it out the top (or high back). Simply because hot air rises, this keeps everything moving better.

The Cosmos is again a great example of this principle. The intake fan is actually on the bottom of the case towards the front. Then is exhausts the air out fans on the top of the case and one high on the rear.

I don't have any hard data to back this up though, so take it for what it's worth.

 

[Zepper]

Yeah, I thought my front bezel was on very tight as well. I worked around the edge of the bezel with a table knife as it sounded as if it might break if I just kept pulling - the side panels were tight too as others have mentioned.

In the old days, the only exhaust fan in the box was usually the PSU fan, so they ran full speed 24/7. Today, the PSU fans are barely adequate to keep the PSU cool as the choice was made for quiet over cooling. Plus there is the common availability of alternate exhaust fans for cooling the whole system.

.bh.

 

[SilentRunning]

Originally posted by: Zepper
Yeah, I thought my front bezel was on very tight as well. I worked around the edge of the bezel with a table knife as it sounded as if it might break if I just kept pulling - the side panels were tight too as others have mentioned.

In the old days, the only exhaust fan in the box was usually the PSU fan, so they ran full speed 24/7. Today, the PSU fans are barely adequate to keep the PSU cool as the choice was made for quiet over cooling. Plus there is the common availability of alternate exhaust fans for cooling the whole system.

.bh.

I removed the front bezel by gently squeezing and pushing on the plastic clips with needle nose pliers.

I really like the appearance of the CM-690 case. However, I wish they had made the side panels fit better, used thicker metal for the side panels, made the holes in the drive cage larger, used the same style clips to attach the front panel as they used to attach the top panel, and included a optional filler panel to replace the top mounted ports (I would love to yank that esata port.)