case fan placement and such

[theashmonkey]

just beginning to mod my old thermaltake damier case spray paint and designs are all sorted just waiting for money now :P

only thing im slightly perplexed over and that is which way round to place case fans so they will either blow or suck? obviously a sucker at the front and blower at the rear just want clarification really - also does it matter what make you buy i guess there all generic?

please correct me if im wrong lol

any advice is helpful - many thanks - Ash

[x88x]

only thing im slightly perplexed over and that is which way round to place case fans so they will either blow or suck?
Air goes in the open end, and out the end with crossbraces. There's also often an arrow or two on the body of the fan that shows either the airflow direction, the fan spin direction, or both.


also does it matter what make you buy i guess there all generic?

Yes and no. Don't take this the wrong way, but this is kinda one of those questions where if you have to ask then the answer is probably no.

Aside from size, the main features of computer fans that differentiate them from others are airflow volume, usually measured in Cubic Feet per Minute (CFM), and noise level, measured in dBA. Generally, there are three different types of people who care about their fans: people who want maximum airflow no matter the noise (http://www.newegg.com/Product/Product.aspx?Item=N82E16835706022), people who want as little noise as possible (http://www.newegg.com/Product/Product.aspx?Item=N82E16835185088), and people who want maximum airflow with minimal noise (http://www.newegg.com/Product/Product.aspx?Item=N82E16835226012). Going down any of these paths will quickly increase the cost of fans, which is why I say that if you have to ask you probably don't need them. For example, the fans I am using in my case (http://www.newegg.com/Product/Product.aspx?Item=N82E16835185057) are fairly cheap for what they are, but they still cost $9 each. In contrast, you can get a cheap 120mm fan for less than half that.

In general, you want the largest diameter possible because the larger the diameter, the more air you can push per dBA.

[d_stilgar]

I'm using these Scythe Slipstreams (http://www.newegg.com/Product/Product.aspx?Item=N82E16835185057) as well. They are really really nice. Almost silent but move plenty of air.

As far as placement goes you want to keep things fairly even. If you have two fans blowing into the case, then you want two going out. It will vary from case to case how things can be set up, but try to keep things generally even. Also, you want to have fans that are close to each other to blow in the same direction, ie fans in the front or bottom all blow in, fans in back or top all blow out.

If you want to get really sophisticated you can always look into fan shrouds or you can get some smoke so you can track where the air is going when it enters your case.

Good luck!

[x88x]

As far as placement goes you want to keep things fairly even. If you have two fans blowing into the case, then you want two going out. It will vary from case to case how things can be set up, but try to keep things generally even. Also, you want to have fans that are close to each other to blow in the same direction, ie fans in the front or bottom all blow in, fans in back or top all blow out.

Thanks, I forgot to mention that.

To add to that, this deals with with we call the 'pressure' of the air in your case. Ideally, you want to have neutral pressure, or, the same amount of air entering your case as leaving. If you have more air entering than leaving, you will have 'positive' pressure, and conversely, if you have more leaving than entering, you will have 'negative' pressure. Neutral pressure is best because then air is constantly flowing through your case the way that whoever designed the case (be that you or the manufacturer) intended it to. If you have positive pressure, air will pool in certain areas, resulting in hot spots in your case. If you have negative pressure, air will be pulled in through any openings available, and certain areas in the case may not get adequate airflow.

[Trace]

Using positive airflow, however, can be beneficial, if you are in a dusty environment. Positive pressure allows you to control where you are pulling air from, and install dust filters, or just choose the least dusty intakes.