Sorry if this has been discussed before but I couldn't find anything specific to this.
In my neverending quest to find the right balance between cooling and silence, I noticed the air coming out of my rear exhaust was on the cool side whereas the PSU and top blowhole fan were expelling pretty warm air.
I concluded that (a) the PSU and blowhole fan were adequate enough to push out the hot air and (b) the rear exhaust fan was expelling useful (cool) air that should stay in the case. So, I turned it around.
Results: CPU temps dropped by about 3-4 degrees and the max under load didn't seem to go up when the ambient temp went up.
It makes sense since the CPU HS is getting fresh air from the outside (like how ducts work). I was able to turn down the CPU fan a good bit without affecting cooling. My PSU has not ramped up at all.
I'm also guessing that I can turn down the front intake fans since there's a new intake fan. I know that my VGA silencer relies on the front intake (I've tested this) so I can't turn them down too much.
So, any cons to this? More air turbulence because of intake air coming in from opposite directions (albeit, at different vertical levels)? I'm also guessing I have positive air pressure in the case. I'm unsure if this is necessarily good or bad.
Making rear exhaust fan an intake fan
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Steve Rosenthal
- *Lifetime Patron*
- Posts: 40
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- Location: Bay Area California
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Check out the following link:
http://www.sunbeamtech.com/new/products ... %20kit.htm
(I've played around with this kit a little, but didn't see any major temp changes, but I'm still tweaking around and may try it again.)
I think the keys here are: redirect the exhaust from the PSU so your rear intake doesn't ingest warm air; use some type of ducting to focus the intake air directly over the HS/F.
I've seen many good examples of DIY ducts here. It's pretty inspiring.
A big advantage that I see for using a rear or side intake is shortening the airflow path to the HS/F.
Does your case have provision for two rear exhaust fans -- not counting the PSU? My case has only one exhaust fan mount, but I've been thinking that a two-fan layout would allow for both a rear intake ducted to the HS/F while still maintaining a case exhaust fan.
--Steve
http://www.sunbeamtech.com/new/products ... %20kit.htm
(I've played around with this kit a little, but didn't see any major temp changes, but I'm still tweaking around and may try it again.)
I think the keys here are: redirect the exhaust from the PSU so your rear intake doesn't ingest warm air; use some type of ducting to focus the intake air directly over the HS/F.
I've seen many good examples of DIY ducts here. It's pretty inspiring.
A big advantage that I see for using a rear or side intake is shortening the airflow path to the HS/F.
Does your case have provision for two rear exhaust fans -- not counting the PSU? My case has only one exhaust fan mount, but I've been thinking that a two-fan layout would allow for both a rear intake ducted to the HS/F while still maintaining a case exhaust fan.
--Steve
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mr_pickles
- Posts: 34
- Joined: Wed Oct 22, 2003 7:05 am
mr_pickles
I don't think this kit is a good choise - no other duct type impedes flow as much as a long goffered tube like Sunbeam's. My advice is to make your own one, keeping these two things in mind:
1. The duct's inner surface has to be as smooth as possible in order to minimize turbulence.
2. The duct's length has to be kept at minimum - same reason.
Example:
I don't think this kit is a good choise - no other duct type impedes flow as much as a long goffered tube like Sunbeam's. My advice is to make your own one, keeping these two things in mind:
1. The duct's inner surface has to be as smooth as possible in order to minimize turbulence.
2. The duct's length has to be kept at minimum - same reason.
Example:
Get your Wiss snips and make a side blowhole for ducting ... I just did!
you get a straight airpath to the CPU - less noisy and more efficient.
by the way mr_pickles the one issue with a rear intake is that if it is next to the PS exhaust you can suck in hot exhaust. You can make or buy a chimney thing to direct PS exhaust elsewhere - upwards perhaps.
And a note about what should be intake and what should be exhaust - you should have about the same CFM on intake and exhaust ports for max efficiency This does not apply if you have large passive ports, in which case you're probably better off dedicating all fans to either intake or exhaust.
the wesson
you get a straight airpath to the CPU - less noisy and more efficient.
by the way mr_pickles the one issue with a rear intake is that if it is next to the PS exhaust you can suck in hot exhaust. You can make or buy a chimney thing to direct PS exhaust elsewhere - upwards perhaps.
And a note about what should be intake and what should be exhaust - you should have about the same CFM on intake and exhaust ports for max efficiency This does not apply if you have large passive ports, in which case you're probably better off dedicating all fans to either intake or exhaust.
the wesson