[Bubba]

The Antec 900 has a place for an optional fan on the side panel. Should it suck air into the case (onto the GFX cards) or blow it out of the case like the rear fan does? When dust cleaning, should I used compressed air to blow the dust out or a vacuum cleaner (plastic attachment) to suck it out?

Also I have a nVidia 790i Ultra Mobo. It has pins for several case fans including the CPU fan. How do I set up the BIOS to have them work on auto? I thought I had done that, but they are on full speed all the time.

[mctw]

what fans do you currently have, and which way are they set?
ive found that roughly the same number of in and out works best, with air in at the bottom (mainly front) and out at the back top.

[Bubba]

The antec 900 comes with four stock fans 3 120mm and one 200 mm. The 200mm is on top of the case and sucks air into the case. There are two 120mm fans on the front of the case one midway that sucks air past the hard drive (the way I have it mounted lol) and one at the bottom the sucks air onto the graphics cards (i have 2 9800GT2's). The other 120mm fan is at the upper rear of the case and blows the hot air out. my dilema is that I can't figure out if the optional side fan is supposed to blow air onto the GFX cards or suck the hot air they blow off outside the case. Right now where that fan would go is just a vent.........

EDIT: Here you can get a look since I probably didn't describe it well. http://www.antec.com/us/productDetails.php?ProdID=15900

[thingie2]

I would probably get it to blow in, afterall, a little extra cool air blowing onto your GFX card and possibly onto your NB never hurts and you've got that 200mm fan to exhaust all the air, so you should be fine

[Carbon]

Looking at it now, I've asked myself the same question.

The advantage of it sucking out the side is increased airflow through the case, especially away from the motherboard and CPU. In would provide a lot of flow, but I'm worried about a backdraft because that 120mm in the back would have a difficult time pushing all that air out the back. You're essentially pushing air in every single area except the 120mm in the back. Not a great scenario.

I think the 200mm draws air in, I'm not sure about this though. I've noticed a lot of dust on my empty fan socket on the side, so it looks as if that's the case. You're creating a nice tunnel through the front, but once that 200mm on top gets in the mix, it starts pushing air in, and sideways off the motherboard and HSF, and that messes it all up and provides inadequate northbridge cooling.

If you care to do a little experimentation, install the 200mm upside down and have it blow out the top, then add the 120mm on the side pointing in. That way, you have the two in the front and the one on the side blowing toward the graphics card and then the 120mm on back and 200mm pulling the air out. This should also give a lot better cooling to the CPU. The 200mm and 120mm will handle pulling the air around the CPU and graphics cards, respectively.

If you don't care to mess with that, mount the side 120mm so that it sucks that air out. Then the 120mm in back will do its cooling job and the side 120mm will help pull the rest through the case, as well as deal with all the air the 200mm on top pushes in.

Also, always use compressed air. Vacuums can hold static charges.

[thingie2]

Seems strange that the 200mm would blow in with it being at the top at the back (where all the hot air goes) so I would do what carbon said, switch the 200mm round so it blows out, then mount the fan to flow in.

[Bubba]

Yeah, it always struck me as weird as well., but it (the 200mm) definitely sucks in.

I'll try that Carbon, that is if I can get to the screws on the 200 without taking everything else out........ if it turns out I have to take the MoBo out to install this cooler then it's a moot point. Haven't read those instructions yet.

Any thoughts on the BIOS controlled speed of the fans/ I can link you with a download of the manual, or copy paste the pertinent parts if you have time to look at it....

Edit: Heck, If I have to take the MoBo out to install the CPU cooler the vacuum/compressed air question is moot. I'll just put the dang empty case in the dish washer lol.

[Bubba]

Well it's not a moot point. I have to take the MoBo out. Nothing is ever simple is it?

[Bubba]

I hate you Carbon. You won't believe what a nutroll it was to take the top and the top fan off without breaking anything.

Lacking info on the BIOS controlled fans, I think I'm going to set the two exaust fans on High and the three intake fans on low and not use the MoBo to control them until i can learn enough to do so. The exhaust fans will not only have to "fight' the three intake fans, but they also have to rid the case of the heat generated by the CPU cooler fans and the two fans in my two GFX cards. If they draw more air than the intake fans generate that should be no problem either as they will merely suck the additional air past the intake fans causing them to spin faster without using more power; IE generating more heating by using more electricity.

EDIT: Or at least that sounds good to me.

[Carbon]

Good to see you understood what I meant, I was a little verbose. I didn't even think about doing the variable speed stuff, that should work well, and if it's higher you're right that it'll pull air through the case a lot easier due to pressure equilibrium and to whatever speed the exhaust fans can handle naturally.

I feel your pain, I absolutely hate taking the motherboard out on this case. I loved it at first but man, I'd rather have something like a P182 or a Lian-Li with a motherboard tray.