Go Back   Hardware Canucks > CASES & COOLING > Air Cooling

    
Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old August 11, 2011, 05:45 PM
Rookie
 
Join Date: Jul 2011
Posts: 35
Default Are there rules for fan air flow direction

When adding fans beyond what is supplied as standard are there any rules-of-thumb to suggest airflow direction? Should it be equal volume in-out, case positive pressure (more fans blowing in than out) or case negative pressure?

When adding additional fans to a case (cutting openings) assuming that there is adequate space should additions be prioritized to the side(s), top, or bottom? Inlets towards the bottom & outlets near the top (heat rises)?

Is there a science to this or is it pretty much luck?
Reply With Quote
  #2 (permalink)  
Old August 11, 2011, 05:57 PM
Lpfan4ever's Avatar
Hall Of Fame
F@H
 
Join Date: Sep 2008
Location: Calgary
Posts: 2,726

My System Specs

Default

I think most people aim for positive pressure, or at least equal. Positive means less dust.

As for new fans, I'd say imagine the case was cut in half from to the top of the front to the bottom of the back. Anything in the half closest to the front would be intake, other half out. If you were to cut a hole in the side panel for the video card though, I'd probably do that as intake if your card has a cooler that expells heat out of the back. If it spills the heat into the case, I would probably say exhaust just to get the heat out of there quicker and not have it effect the rest of the components.
__________________
Quote:
Originally Posted by encorp
I don't know, maybe if you get a big enough compacticator you can put it in your butt and name yourself "sexbuttplug"...
Code:
<martin_metal_88> I think I am gonna sell my server
...
<firebane> i will offer pereniums mom
<firebane> slightly used
<Keltron> slightly is an understatement
<LPfan4ever> Who're you kidding...slightly?
<martin_metal_88> peri's mom, slightly used? lol...

Reply With Quote
  #3 (permalink)  
Old August 11, 2011, 06:00 PM
Hall Of Fame
F@H
 
Join Date: Feb 2010
Location: Markham
Posts: 1,564

My System Specs

Default

Quote:
Originally Posted by Dunc View Post
When adding fans beyond what is supplied as standard are there any rules-of-thumb to suggest airflow direction? Should it be equal volume in-out, case positive pressure (more fans blowing in than out) or case negative pressure?
Positive case pressure is usually better, however there are a few scenarios where negative pressure is more beneficial.

Quote:
Originally Posted by Dunc View Post
When adding additional fans to a case (cutting openings) assuming that there is adequate space should additions be prioritized to the side(s), top, or bottom? Inlets towards the bottom & outlets near the top (heat rises)?
Side fans generally pose more of an acoustic liability, but a side intake can drastically reduce GPU temps depending on configuration.

I would still prioritize top and bottom holes over a side fan though. But it would also depend on your case.

Quote:
Originally Posted by Dunc View Post
Is there a science to this or is it pretty much luck?
Not much science, not much luck, more like trial and error. Which is sort of like science I guess.
__________________
Reply With Quote
  #4 (permalink)  
Old August 11, 2011, 06:05 PM
Top Prospect
 
Join Date: Jun 2010
Location: Wolfville, Nova Scotia
Posts: 69

My System Specs

Default

Generally speaking, any case fans on the front, bottom, and left side panel (if facing the front of the case) you'll want to have in taking cool air, and any fans on the rear, top, and right side panel (if facing the front of the case) you'll want to have exhausting hot air. That said, you should always try to balance the number of fans in-taking against those exhausting.
Reply With Quote
  #5 (permalink)  
Old August 11, 2011, 06:30 PM
Banned
F@H
 
Join Date: Aug 2007
Location: mtl
Posts: 12,694
Default

what case you got again?

lately ive favoured more exiting than intaking
Reply With Quote
  #6 (permalink)  
Old August 12, 2011, 09:34 AM
Top Prospect
F@H
 
Join Date: Sep 2007
Location: Canada Eh
Posts: 112

My System Specs

Default

I've always figured Positive Pressure - less Dust, Negative pressure - Slightly better Cooling (The 'ol low pressure temperature drop). lpfan4ever's cut the case in half scenario is very well put and dead on IMHO.
__________________
Cheers; Snarl

Another Guy From Canada
Reply With Quote
  #7 (permalink)  
Old August 13, 2011, 09:34 PM
Trial Member
 
Join Date: Aug 2011
Location: Medicine Hat, Alberta
Posts: 1

My System Specs

Default

I have always tried to keep the airflow In/Out pretty close, but slightly positive. Also make sure that you have your case wiring as neat as possible to prevent airflow blockages.
Reply With Quote
Reply


Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Don't know which direction to go (AMD or Intel) BootlegUsher New Builds 22 December 18, 2009 07:21 AM
Aren't they going in the wrong direction? redwagon Video Cards 19 November 13, 2009 12:51 PM
Zerotherm BTF90 fan direction Billyh Troubleshooting 2 October 25, 2009 07:49 PM
change the direction of my gx2 fan kyle_L Video Cards 8 December 18, 2008 01:35 PM
Need direction, help, insite......... Sitkaspruce Troubleshooting 6 April 26, 2007 08:40 AM