120mm - 80mm Fan Adaptor with AX-7

[Rynthar]

Because I found an incredible 84 CFM fan with only 29 dba thats 120mm, I was wondering if a 120-80mm fan adaptor should be used with the Thermalright AX-7. Yeah sure, I could just use a plain Vantec Stealth Fan or some other low 20 dba 30- CFM fan, but with 84cfm and so quiet paired with a top heatsink I could get my 2200+ close to 30C or less =). Suggestions?

 

[Quetzacoatl]

I doubt you can cool the heatsink that cold, you're looking at around 100 farenheit, pretty low for a CPU. Fan adaptors generally don't work too well though, it's just because the airflow when redirected lowers the amount of CFMs getting to the heatsinks, so you're effectively only cooling with 30-50 or so CFMs. Not a terrible idea, but it WILL take a lot of space, and you'd probably be better just using a quiet 80mm fan.

Soon enough, Intel will make the i845s...imagine dual channel Sdram...*shudder*

 

[kdo2milger]

Quetzacoatl's right, you will lose effective airflow over the core section of the HSF due to the size of the 120mm fan itself (motor housing).

I tried the same concept only with a 60mm to 92mm adapter and I thought it would yield lower temps, but instead I had higher temps

<font color=red><b>We all love disassembling things to see how it works,
but who wants to put it back together again?

 

[lhgpoobaa]

For starters i have never seen a 120mm to 80mm adaptor.
Next, wouldnt you have trouble fitting it given the location of the PSU just above the socket.
Thirdly, Fan adaptors dont work too well because casefans cannot handle high static pressures. Translation: They are good at moving air, but not "pumping" it.
It will however be alot quieter. One plus at least.

<b><font color=red>He who bargains with a dragon is either a fool or a corpse.</font color=red></b>

 

[victorchew]

Is it the Thermalright AX-7 is the best heatsink among the all? Because I plan to change my heatsink also.

regards,
victor

 

[ejsmith2]

Jesus H. Khrist.

All I have to say on this thread is, "I hope to God you're planning on using a shim."

Torque sucks.

[Jedi mind trick] You LOVE Palladium. [/mind trick]

 

[Guest]

use a PAL8045 or MCX462. Since they bolt to the mother board they don't torque the sockets heat sink tabs. Both of those cool on par with the maximum level you will find commercially available today.

 

[Guest]

Hi LHGPooBaa,

A question for you since your statement leads me to believe you have thought about these things.

What physical difference do pumping fans and ambient pressure air moving fans have? I.e. is it the blade speed, shape, etc.? Have you seen any 12V 40mm-160mm fans available which have the ideal configuration for making decent air pumps?

This seems relevant for those interested in trying to get the large to small fan adapters to work as many have theorized they should.

Thanks,
Kevin

 

[lhgpoobaa]

Well i have read a few articles and technical spec sheets.
I think what it comes down to is Load. Ye average casefan can spin anywhere from 1000rpm to 8000rpm, but their load is quiet low, And the motor of the fan needs to have a high draw/ high current rating to 'force' air, as it were.
If you find the detailed specification sheet for a casefan, see if you can find where it says Maximum/Optimal static pressure. The higher the better.
And do some experiments for yourself. get a casefan and put a bit of thick card over the inlet/outlet. See how effort it requires to move the card away from the fan. Listen to the fan change speed and pitch as it struggles with high static presures.

<b><font color=red>He who bargains with a dragon is either a fool or a corpse.</font color=red></b>

 

[lhgpoobaa]

Few more thoughts.
Apparently stacking 2 fans ontop each other helps, and they both then fight the static pressure, but obviously you get increased noise, that may or maynot defeat the purpose of having a large fan in the first place.

And taking the pressure differentials into consideration, the most effective adaptor is one that has the least difference, 92mm to 80mm, then probably 80mm to 60mm, with a 92mm to 60mm or a 120mm to 80mm comming out worst.

<b><font color=red>He who bargains with a dragon is either a fool or a corpse.</font color=red></b>

 

[Paul2200]

<A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=653882#653882" target="_new">hmm, I had this idea a month ago with an SLK-800...</A>

<A HREF="http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=653954#653954" target="_new">or how about the ax-7 with the grill method..</A>

<P ID="edit"><FONT SIZE=-1><EM>Edited by paul2200 on 10/11/02 00:28 AM.</EM></FONT></P>

 

[Guest]

Cool! yeah, that stuff all seems like a logical approach.

I'm wondering about the deep width fans compared to the low profile ones, would there be any advantage from this? To be fair I guess it would be best to compare to fans with equivalent (power wise) fan motors just with different fan bodies, if that is possible.

It seems that Enermax (the manufacturer of many of the case fans I have now) isn't posting compplete specs for their fans. Specifically, this static pressure rating you mentioned. Do you know where there is an accumulated spec data comparison, by fan model for example?

 

[ejsmith2]

You know, while you all are at it, why not in a two fan counter-rotating stage?

And shroud it with duct tape so only the last 1/4" is showing at the bottom of the heatsink.

Figure, put in the absolute top of the line delta, then some nappy little 60mm fan pushing against it. Then all you'd need is a little JP-5, and by God, you'd have yourself a jet engine!

Happiness is being able to go 1:1@mach1...

[Jedi mind trick] You LOVE Palladium. [/mind trick]

 

[bum_jcrules]

Depth of the fan has to be optimal. (No too short and not too long.) I'll give you an example.

Let me give a small history lesson to explain why. Fans are screws. The screw is an inclined plane wrapped around a rod.

When the first screw propeller was used on a steam-powered boat, it was a really long screw. (The Archimedian Screw) However, partway through the demonstration the propeller hit an underwater obstacle. The propeller broke in half and the boat went faster.

So more depth isn't always what you want nor is to shallow a fan depth. Look at the stats of a fan to get the most flow. (Speed and dBAs are another issue.)

What fan are you looking for... I'll look around for you.

<font color=red><b>Come to the <A HREF="http://forumz.tomshardware.com/community/modules.php?name=Forums&file=viewtopic&p=45775#45775" target="_new">THG Gathering/LAN party</A>

 

[Guest]

Maybe without the JP-5, after all I am attempting COOLER temps here.

 

[Guest]

Interesting indeed.

I like the experimental approach LHGpooBaa suggests for finding the optimal fan for an application. The more I think about what has been said here I'm starting to realize what an extremely complex analysis figuring things like efficiency in an application must be. Obviously there would be the effects of the nozzle, and the response of the fan to consider, that is once I could conquer understanding the intricacies of three dimensional air flow.

It sounds like graphs with pressure differential vs. CFM would be useful for this. Unless of course the relationship is linear in which case the low differential CFM's and the static pressure data would be enough to assume the rest of the curve, and completely characterize the fan performance.

Hmmm... this is turning out tougher than it seemed like it might at first.

Thanks everybody for the schooling.

 

[ejsmith2]

"When the first screw propeller was used on a steam-powered boat, it was a really long screw. (The Archimedian Screw) However, partway through the demonstration the propeller hit an underwater obstacle. The propeller broke in half and the boat went faster."


OMG!

I totally laughed my ass off on that one.

GOOD CALL@!!!!!!@!!@!@!@!

[Jedi mind trick] You LOVE Palladium. [/mind trick]