Suck or blow? (CPU fan)

DaggaDagga · 10-07-2006, 22:07

Should a CPU fan blow cool air into the heatsink or suck the heat off it?

Just wondering which way up to put my fan. In my mind's eye, I would imagine blowing pushing cool air into the bootom of the heatsink better, but sucking would pull the heat away from the motherboard instead of blowing it all over it.

Is there a right or wrong way?

TheBlueRaja · 10-07-2006, 22:09

Most heatsinks (standard ones) are designed to have air blown onto them.

Some heatsinks are designed to have air pulled from them.

It just really depends on the heatsink. Something I might try is to try each one and use a program to monitor your temperatures. Compare the temperatures and see which one work the best.

You should set the fan to suck air from the heatsink or blow air on the heatsink according to the specifications of the manufacturor. If you're using the fan that came with your CPU, leave it as is. If you try to change it, you're responsible for whatever happens to your CPU.

Manufacturors design the heatsinks with an airflow in mind & nothing will guarantee that will work well if you decide to change that.

10-07-2006, 22:14

Blow FGS dont suck lollol

Ive never seen a cpu fan suck (except the 4.99 stock jobbies you get with them

and thats got nothing to do with airflow btw lol)

Skatoony · 10-07-2006, 22:25

The only fans I have seen suck are radial fans, but they're only ever used on graphics cards.

AndrewJ · 10-07-2006, 22:27

I prefer the girl too....(reads thread title better... )

I think blow.

DaggaDagga · 10-07-2006, 22:34

Ta very much. I've never bothered to take a fan off a heatsink before, but I've just got a 80mm-60mm adaptor together with an 80mm quiet fan.

I also have a thermostatic fan speed controller, so I will be able to see what it's doing. I might try sucking aswell, just as an experiment. Fnarr fnarr.

This is for my latest beast of a PC - it's a 600,000,000Hz monster computer. Cost me ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â£4.20 for the motherboard and CPU off Ebay

. This is just a 1TB file server, so I was after the crappiest spec possible for minimal power munching and noise.

Runs XP surprisingly smoothly. Typing on it right now in fact.

AndrewJ · 10-07-2006, 22:36

I've been thinking of such an adapter myself, where abouts did you get yours from?

DaggaDagga · 10-07-2006, 23:04

Well, the one I got is Akasa, ÃƒÆ’Ã¢â‚¬Å¡Ãƒâ€šÃ‚Â£2.87 from Dabs (quicklink 3058WS). However, it's probably going in the bin coz there's a problem with it - it's got holes around the 60mm area that it screws onto (if you look at the dabs site you should see what I mean).

Have a google and you should find the reviews of it. They all say it's crap, coz the extra 20mm of fan blade doesn't blow through the heatsink. If your 60mm fan needed to run at 2000rpm then your new 80mm one will also need to run at 2000rpm. So pointless then.

I'll have a look elsewhere. I'm after one that's basically a funnel. They are all over the place. I don't understand what Akasa were thinking when they came up with this one.

---------- Post added at 23:04 ---------- Previous post was at 23:02 ----------

Ebay item 160003891971 looks more promising to my little brain.