sp140 or af140 high performance?

hello, just wondering if anyone knew if corsair had any plans of making an SP140 fan or a AF140 high performance fan. I really like the series but I think the af140 quiet edition is a bit underwhelming considering the competition at the same price point.

 

Maybe the tests were made under different conditions but at 24db the af140 produces 68CFM and .84 static pressure compared to the spectre pro 140 that pushes 87CFM at 22.8db with 1.38 static pressure.

 

I much prefer the AF140 looks wise but it gets beaten in every area by that spectre fan so was hoping that maybe corsair might be releasing a higher rpm 140 fan?

We won't know if they will, Corsair doesn't release information for unannounced products.

Oh okay thank you. Also please could someone explain static pressure to me. Ive been trying to get my head around it but you hear something different on each site you go to.

 

Someone said that the static pressure reading given by manufactures is the amount of resistance it can take and still provide flow?

static pressure is the force of the air leaving the frame.

the measurement device uses a sensitive tube, with a measured fluid (h2o) in a graduated scale called a mamometer. the air blows into that tube and moves the water a distance. less pressure moves the water level less and the more pressure the more the water level rises measured in milimeters or inches.

cfm is the amount of air that the fan discharges in a determines amount of time.

hope this didnt muddy the water for ya..

 

airdeano

Okay but then surely a higher static pressure means higher cfm? because to get a higher force you would need to push more air? If anyone could provide the equations that would be awesome so I could see the relationship between force, air needed, cfm etc. Im going to try and find them myself.

 

I have a Obsidian Corsair 550d, if I buy the AF140 as an exhaust fan for the top and rear, what will the effect of its low static pressure be in terms of performance? the top of the case and the rear of it only has a thin mesh so will it make much of a different, what performance increase would I get if I cut holes for the fans?

 

For the front of the case i think i should go with the sp120 as there is only a small amount of space to intake air (due to the front door and all), is that the right choice?

 

For the bottom intake the fan has to pull air through the dust filter and the case grill, more room that the front of the case but no where near as little resistance that the exhaust fans get to deal with as should I go with the SP120 or the AF140?

 

sorry for all the questions but thanks for all the answers. I want to make sure i 100% have my head around this before i start spending money.

I'd go AF140 for exhausts and bottom intake, and SP120 intakes - for the reasons you stated, because you're on the right track.

 

I like to think of cfm as horsepower and static pressure as torque - it's not entirely accurate but the concept is somewhat similar.

 

With high cfm there's a lot of air being blown through your fan, now imagine bringing your palm over behind the airflow and gradually closer and closer...

 

If the fan still pushes hard against your hand when it is very close to the back of the housing, it has more static pressure.

 

This is partly why you see wider and stiffer fan blades on a high static pressure fan - they resist bending under pressure.

 

OK.

 

As to your point about mesh covering exhaust locations - I don't think the end result is at all worth it. It will have next to no airflow benefits and cause issues with exposed spinning fan blades and dust entering when the PC is turned off.

 

HTH!

 

 

 

BTW - Here's a good page for formulas :

 

http://www.comairrotron.com/airflow_note.shtml

Thanks for that link, very helpful. Haven't got round to reading it all yet. Ive just bought 4 sp120 fans. I got 4 because they were £16 for the dual pack or £12 alone and i want three (one over heatsink, two for front intakes) so i will have one spare. the stock fan on the heatsink is pretty decent CFM wise but low on static pressure.

 

I have a £50 Amazon voucher so going to get the rest of the fans when that arrives.

 

Any ideas on what i could use the spare SP120 for? my CPU cooler is the Scythe Rasetsu (http://www.scythe-usa.com/product/cpu/113/scrt1000_detail.html) so cant do push pull unfortunately. To help get the most out of the cooler im thinking of a little mod idea. I have the cooler so the fins are horizontal, as it is blowing down some air will escape to the right of the cooler and circulate in the case so was thinking of putting a layer of card down the right side of the fins stopping air escaping. this means the only places air can get out is down the bottom or to the left (where it will be sucked out the back). Im also going to put some card on the front and back of the cooler at the top so air cant escape from that gap between the fan and heatsink.

 

Also another fan related quetion: I have my PSU facing upwards to act as an exhaust for the case and also to reduce noise but wondering if it will have an impact on my graphics cards cooling performance as it is working against it. I would just turn the PSU over to check but i spent 2 hours doing the cabling so its no small task.

 

Thanks for all the help

A 550D case is designed for quiet PCs. You need to decide what your primary goal is, ultimate quiet or ultimate cooling, before fan and fan position recommendations can be made.

 

Fan specs are basically whatever the manufacture decides to print, there are few standards for testing and so many variables involved. We don't even know what equipment was used in testing the fans, with the exception of Corsair, where some of their equipment is profiled on their website. Corsair is one of the few fan manufactures whose specs I could trust. Comparing their specs to the other fan specs you mentioned IMO is meaningless, since no one officially verifies fan specs. The few PC hardware web sites that do decent fan testing usually find the actual performance is much different than the specs.

 

Static pressure of a fan is important when they are being used to push air through a radiator of a liquid cooling system. Otherwise it is not considered important. Fans supplied with PC cases are usually lower RPM and lower pressure fans, otherwise they would make to much noise for those that want quiet PCs. Another thing to consider is the larger in size a fan is, the lower it's static pressure usually is. That is partially due to the larger fans speed being restricted due to noise.

 

Blocking the sides of that CPU cooler won't do much to prevent heat entering the PC case, since it's a down-flow type cooler.

 

The use of a PS as a cooler or an extra cooler for a PC is rather outmoded IMO. If the air in the PC case is warm, it won't cool the PS as well as outside air.

 

It sounds like you will have one exhaust fan, plus the PS for exhaust. Are you using the side 200mm fan? Are you going for a positive pressure system? No fans on top for noise reasons? Again, what is your main goal, quietness or cooling?

Ah i forgot to mention, i have modded an on/off switch in the front of my case. I use my case for gaming (where i want a good OC and temps) but also mostly for internet, writing essays etc where i want a dead silent PC. The switch is behind the door and if im going to game (or my pc is getting too hot for another reason) i pop the side pannels off, open the door, flick the switch and my case is now airflow optimised. This means fan noise isnt too much of an issue because the only time i would hear it is when playing the game.

 

As for fan configuration. I am going to have 2 120mm intakes at the front, 1 140mm intake at the bottom, 1 200mm side intake, 1 140mm exhast at the rear and 2 140mm exhasts at the top. The PSU is also set up to be an exhaust.

 

The only fans that are always running are the CPU, GPU and rear exhaust. Then when i switch the other fans on the 200mm provides cold air for the GPU which is exhausted by the PSU and also over laps the CPU a bit to provide some more air there.

 

The fans are all running off a single molex. The molex is connected to the switch and then split on the other side of the switch to go to all the fans. I have set it up so i can connect one of the fans RPM (yellow wire) to the mother board to monitor how fast that fan is going. If things are too noise then I can always under volt the fans. I have made a thread about it asking for help on how to make the mod look more professional. I also threw in a bit about the fans at the bottom but I then decided to make a separate thread about it. http://forum.corsair.com/forums/showthread.php?t=107846. A little update to that thread is I have bought a vandal proof switch as they seem like they will work and not be too hard tgo mount in the bay

So my four SP120's have arrived and i have hooked them up to the front. Without the resistor cable these things are really quite noisy (running at 2400 RPM) but i have them running at 1400 and they are quiet (still audible) and pushing some good air, much better than the stock fans.

 

I dont think i am going to connect them to my heatsink, without the PWM controller there isnt much point, they are too noisy at max load and still audible after being quietened down. My current CPU fan runs at 500rpm idle which as you can imagine is dead silent.

 

This means i have two SP120's over. I think I am going to send them back, even though they are good fans they wont push as much air as a 140 fan would