Rad: Push or Pull

[RedPhoenix]

On my heatercore



Now I PLANNED on having it pull air about 1 inch from the rad with 2x85cfm Evercool Aluminum fans. I have had stupulations thouhg on if this would work to cool down 2 pelt blocks with a Hydro L30

If will be a pain to re customize the shroud though... But if the Pull method will sacrafice good temps then I THINK i could redo the shroud.

What I could do in the near future...
Keep the Pull method and later add a push + shroud.
What do you think?

[fhorst]

Nice shroud!

I don't see why you can not turn it around. Anyway most computer fans are made for blowing, and that is what they do best. Fans that have a good suction are the ones who look more like a drill. (Wider, more diagonal blades)

For your setup, a little more input would be welcome.
Where do you want to place the rad? Is it sucking air from the computer case, or outside air?

In your setup, where the intake is not that much restricted by the rad (you have enough space between the fan and the rad) it should not make a big change, as long as the air that's coming in and out has a free flow.

[RedPhoenix]

This will be going in the front of the case.

So it is sucking outside air then.

When it pulls there is 1 inch from the rad. It will be sealed all the way around so only air ir can take it from the rad...

[Sneakytermite]

I don't know if this is true: having two fans in a push/pull configuration can eliminate death spots -> no need for shrouds. When I find out more, I'll post again. Sorry I can't be much of help.

[RedPhoenix]

Alright After I just put the shroud on ( not air tight yet ) and just put the 2 fan on it in pull position. I boiled water to 180F. 82C

an ENORMOUS amount of hot air flew off ( the fans were only at 9v i used a battery ) and the water was cooled to 90F ( 32c) in about 1 min. Dont know how good that is but that is a huge water temp drop.

Comments?

[fhorst]

Originally posted by Sneakytermite
I don't know if this is true: having two fans in a push/pull configuration can eliminate death spots -> no need for shrouds.

Sorry to say that you are wrong here. Every fan has a center, that center is the dead spot. Only if you place the fan about min. 1 inch from the rad, the dead spot will disapear, due to the movement of the air.
Also, if the fan is direcly on the rad, the pressure it needs to press the air through a small surface (only the fan area) is much higer then when it is 1 inch away from the rad. The area it can cover then is much bigger, and therefore it needs less pressure.

To RedPhoenix: a 50c drop in a minute? That’s great!
I guess the water was standing still in the rad at that time. When the water starts flowing, this will only get a lot better.

Looks like you got "nothing to worry" about.

Just a few ideas:
- Blowing the hot air inside your case will be best for the watercooling, as it is beeing cooled with "cold" fresh air, but you need to be sure that the hot air can leave your case! So make sure you have an equal or more fans getting the hot air out.

- A to high overall system temp will make other items fail (memory, chips on your main board etc.)
Using the "hot" air from your case (so not sucking but blowing) will decrease your cooling performance, but you will gain on system performance/stability.

It's a bit trial and error. First let the fans suck the fresh air in, and measure the temps in your case If they are not to high, it's all OK.
If you get high temps inside your case, and your system is getting unstable, turn your fans around, so you reverse the airflow (but leave the PSU for what it is) your cpu temp might go up a bit, but you will run a rock solid stabile system.

What are you planning to cool? CPU, GPU?, North bridge? use peltiers?

[RedPhoenix]

Hydor L30
Maze4-1 226 watt CPU
Maze4-1 80watt GPU
At the moment Vantec Iceberq for NB
soon to go Micropool or That new swiftec block

Thanks. Yah Here it is all together. This damn thing looks like a beast holy crap

[fhorst]

OK, it looks like you are using pelts.... So your coolant temps are getting high!

Looks to me you can better let the rad blow the air outside your case. A case temp of 60c won't do you much good.

[RedPhoenix]

lol I understand that definetly. I will be using otehr case fans though. 2x80 rear exhaust... 1x92mm rear exhaust and 1x80mm blow hole... This be alright?

[Sneakytermite]

Originally posted by fhorst
Blowing the hot air inside your case will be best for the watercooling, as it is beeing cooled with "cold" fresh air, but you need to be sure that the hot air can leave your case! So make sure you have an equal or more fans getting the hot air out.

Have more fans pulling than pushing will create a negative air pressure inside the case so dust on the outside will get it through small cracks. I just make sure the pressure is more on the positive side so dust will enter through my air filter.

Post some pics for us to see man RedPhoenix.

[RedPhoenix]

Only pics i have were before the installation of the rad but here







These the pics you were looking for?

[fhorst]

Originally posted by Sneakytermite
Have more fans pulling than pushing will create a negative air pressure inside the case so dust on the outside will get it through small cracks. I just make sure the pressure is more on the positive side so dust will enter through my air filter.

Post some pics for us to see man RedPhoenix.

You are right. Look at it this way: A little negative pressure, will give the suction fans a better performance.
A lot of negative pressure will make your case all dusty ;-)

To RedPhoenix :
2x 80mm = 1x 120mm so 3 x 80 and 1x 92mm will sure do the trick.
If one 80mm is just a blow hole, with no fan, then that will be perfect also. The pressure that might be to much can come out there.

Great case you have there. What brand is it? It has loads of room in the top, just what I'm looking for my new setup...

[RedPhoenix]

Chieftec Dragon Full Tower Case

http://directron.com/da10bd.html

I removed the front door though I think it looks better IMHO if modded right.




So if I just keep the fan arrangement I have at the moment it should be alright?

[fhorst]

Yep. Just hook things up, and let them rock ;-)

If things get to hot, you can always turn the airflow arround.
As you are using pelts. It won't give much temp difference.

[RedPhoenix]

Thanks for all your help

[Zogthetroll]

a little bit of advice about the whole positive/negative airflow question, negative pressure is your friend. it might help if you guys took a look at pHaestus's article "5 myths of cooling", that covers this very issue. also, i can vouch for it from experience. I built a case that was almost completely sealed off except for the fan holes, and it is definately more important to be sucking out the hot air than to try to force air in. also, it has been said numerous times around here in the push vs. pull debate on fan mounting that fans are more efficient when pulling air through a rad than pushing (i think you only get like a 40% increase when both are used) and the same thing applies w/ the pressure in a computer case. with the fan setup on the computer i mentioned earlier i noticed the most improvement when i added exhaust fans (if you've got hot air coming out of any of your exhaust fans, it probably wouldn't hurt to add more) and when i cranked the front fans up and switched over to positive pressure in the case it did nothing for my temps, only blew air out of the drive bays (which is covered in the article here at procooling) so if you're at all concerned w/ how quiet your pc is (ie, trying to use as few fans as possible) it would make sense to use them as efficiently as you can. anyway, my $0.02

*edit* oops, didn't see fhorst's post. i agree, sounds like a good fan configuration. even better if you've got some voltage adjustment on those suckers. btw, how are the evercool fans? i've been looking at maybe getting those (i'd get a blower but i'm pretty sure that won't fit in my case)

[RedPhoenix]

Thanks again

The evercool fans are nice... I never had any other 120mm fans before so I cant vouch for how quiet these are compared. No whining noise or anything only noise is the air flying out. I like them a lot. 7v is silent whihc is calming but gaming and such ill stick around 10-12 v

[Sneakytermite]

RedPhoenix, do you mind giving me the link of the heater core that you're using? Thanks man. The system looks great dude. I'm jealous.

Water on my man.

[RedPhoenix]

Of course

I got it at www.PartsAmerica.com type in 2199 in search Its by Fedco

It was $18.88 USD

http://www.partsamerica.com/PartDeta...artNumber=2199

You will have to enter your Zip Code

[Gooserider]

Zogthetroll:
btw, how are the evercool fans? i've been looking at maybe getting those

The folks over at Silent PC Review seem to think very highly of them, particularly the aluminum frame models. General concensus is that they are quiet aside from air movement noise at all voltages, comparable to or better than Papst and Panaflo's. They undervolt well, and are reported to move lots of air at low voltages when compared to other fans.

I'm sure there are fans with better air movement ability, but they aren't as quiet, which is the big thing at SPCR.

I'd be a little nervous about them as rad fans as 25mm thick fans generally don't do as well working against a restriction (and a rad is pretty restrictive) as 38mm fans do, all else being equal.

Gooserider

[RedPhoenix]

Alright Goose. Take that into consideration. When I finally get my setup I can test it. If the fans dont cool it down good enough I will change the shroud.

[Sneakytermite]

I'm really jealous RedPhoenix. Your heater core can't fix in my case unless I remove both of the hard drive cages and the floppy cage too since I have the mid-tower version of your case. Go with Panaflo fans and use a fan controller. I don't think those Evercool fans can do better than Panaflo. But this is just my opinion.

Good luck dude and keep us posted.

[V12|V12]

I must say, nice case man! Now on to what I've noticed:

1)Negative pressure IS better. Through experience, I've got 1x80, 3x92, 1x120mm and trying diff setups between them, I've found that my lowest overall case temps work best with the 2x92's exhausting, 1x92 intake and 1x80 exhausting...

2) If you could; my 120mm had a triangular shroud where the fan is on the bottom of the inner portion of the case, Pulling air through my HC from outside and directly exhausting it out to bottom of the case, as to avoid adding MORE heat to the case.
What you must understand is that CASE temp DIRECTLY effects water cooling temps, not as much as air, but think about it; Your HC is directly inside a box. The hotter the inside of the box, the LESS efficient your HC will be and the more temp load it will face. If you keep your case cooler, then it aids in the cooling with the load the HC has to tackle.

3) 25mm fans just don't produce enough pressure, pos or neg for me. I've got a 38mm and a monstrous 50mm and they both move more air per blade revolution, just based on common sense, thicker = more air moved by thick blades. They don't have to work as hard either to move more air. And they are usually quieter since there's more Tube for the air flow to be smoothed (Tube-Axial/Vane fans).
*** Try this, becareful though*** Take your fan & put something against it to partially block the air from exhausting, now take your hand and put it near the intake you'll notice that you actually feel some air blowing BACK out the intake from all the exhaust blockage... Now do the opposite, partially block the intake and put your hand near the exhaust... notice some air comes out... Now if you run a negative exhaust setup the extra neg pressure will aid in helping the HC fan pull in more air. Now if you make a shroud like I did, and if nothing's blocking the exhaust, the air has NO WHERE to go but through the HC--> fan intake and out the exhaust... Blowing though, the air can escape between the small space between the blades and the fan's frame.
*One more thing, when you try (if you do lol) the 1st pressure test, you'll notice the noise level is SIGNIFICANTLY increased, where as the 2nd scenario the noise level is much lower.... based on my experience/experiments Neg pressure is better, most PC fans aren't designed for high pressure loads...

Luckily the depot I live near carries nothing but INDUSTRIAL grade cooling fans (All metal frames, Thick magent/wire gauge saturators, some all metal construction!) fans designed for horrid temps and working environment. Comair/Rotron, Nidec Torins/Boxers, Papst Boxers are all some SUPER grade fans. If you get them new they are pretty pricey... used, I got a Rotron 120x38mm Whisper XL (new $43) for $5! Good luck with your cooling adventure!

[RedPhoenix]

WOW! Great POST!!!! Thanks.

Alright... Can someone recommend good 120x38 thick fans that can be quiet without a huge sacrafice in CFM

[Levish]

http://www.newegg.com/app/viewproduc...ription=120x38

Panasonic Panaflow 120x120x38 114.7cfm 45.5 db 6.12w