Water Cooling Radiator Fans

hey guys,

so i started to work on my WC but i am having a hard time understanding whats the best setup for the radiator fans. I am going with a 320 rad in a 800D case and the rad will be mounted in the roof of the case (on the inside). now here is where i get confused:

1) should the fans be installed on top of the rad or on the bottom (meaning between the case and rad or under the rad)?

2) should the fans pull air from the outside inside the case or would it be better to have the fans pull the air from inside the case and push it up outside the case?

Thanks

Snir

1. what speed fans are you going with? if below 2000rpm then have them pull air through the rad (so --> case|rad|fan --> ). if you have fans above 2000rpm then have them push air through, (so --> case|fan|rad --> )

2. it would be better to have the fans pull air from the outside into the case as the ambient temp outside the case will be lower.

Pulling or pushing the air from the rads makes somewhat of a difference. Depends on the rad and the fans, the layout, using a shroud etc. So unless you really read tons of posts, knowing some of the science and understanding charts it's a crap shoot.

You didn't give us much info to go on.

We can guide you, mainly by linking you to tests done by others. It's how we learned.

So, lets let that slide for now, more importantly........

You really need to think of one of the basic helpful hints. Coolest air to the rad results in the best temps. MOST of us always use cool room air into the rad, not using warm case air through the rad. There are many other ways, but I'm pretty sure we all agree the primary rad should NOT use warmer case air if it can be done that way. Yes, your mobo and HD temps will be a bit hotter, but believe me, they don't mind a bit higher temp.
Not saying it has to be that way. If the rad is plenty big to dissipate the heat, your Delta T temps (something you should understand somewhat) are fine, your load temps are fine, then exhausting out of the case is fine.

Great info, thanks! the fans i am going with are the late Yoon medium speed fans and the radiator is the swiftech MCR320.

Perfect match of a rad and fans. UMMMMM, you do know the fans your looking at are sleeve bearings. They don't last a real long time in a horizontal setup like on the top of a case. Might need to look at bearing fans. May I suggest the Scythe Gentle Typhoon 1450 RPM or even the 1850 RPM ones. Great stuff.

Conumdrum said:

Perfect match of a rad and fans. UMMMMM, you do know the fans your looking at are sleeve bearings. They don't last a real long time in a horizontal setup like on the top of a case. Might need to look at bearing fans. May I suggest the Scythe Gentle Typhoon 1450 RPM or even the 1850 RPM ones. Great stuff.

Click to expand...

you sure can how long do they normally last? i might just pick up the schyte if these will only last me a month

Naa, maybe a year or so. No conclusive data. So you'll be fine for a long while, just informing you.

Sweet! i will stay with the loons since i already bought them but i will make sure to keep an eye on them and also order the other ones down the road to minimize downtime if they fail

Blonde,i remember that from a week ago when you made a thread for choosing the watercooling parts you posted that you will order mcp355,swiftech xt,mcr320,compressions and etc and this list contained scythe gentle typhoon fans so why did you go with yateloon medium fans ?

Conumdrum said:

May I suggest the Scythe Gentle Typhoon 1450 RPM or even the 1850 RPM ones. Great stuff.

Click to expand...

I've seen a lot of recommendations for the Gentle Typhoon and was wondering why they've gained prominence over the S-Flex? I can't see any difference to speak of between them except the RPMs. The cost, noise, and flow all seem very much the same (except MTBF is higher for the S-Flex). Honestly, I'm not even sure why Scythe introduced the Gentle Typhoon except to have a new label so I'm obviously missing something here - what is it ...?

QI, the GT fans are 9 bladed with highly swept back blades compared to the S-Flex's 7 blade impeller. So they make a totally different pitch noise than the S-Flex, which is less irritating to some folks. That's the main difference between them, IMO. The GT fans also have some honestly rated cfm and dB numbers, just like the S-Flex too. It does have a bigger hub than the S-Flex though, which means a bigger dead zone. That isn't a problem on a rad with a plenum and especially in push, but could be a problem in a pull setup on a rad with a short plenum or no plenum at all.

Buy yourself an 1850 rpm version next time you are making an order somewhere just to try it out. You will be pleasantly surprised at the way they run.

I can see the pitch changing - hadn't thought of that since the db was so similar. I've got some S-Flex G's around here to use for comparison to the 1850 so I'll give it a try next time I order from Sidewinders. Thanks, muddocktor ...!

I can tell you that the G S-Flex is much noisier. I would suggest comparing them to the F model S-Flex since it's more similar to them in cfm and loudness.

I was looking at the wrong table. Yeah, 'F' it is LOL! I've got some of those, too, and one 'E', which to me is dead quiet ...

seeka12 said:

Blonde,i remember that from a week ago when you made a thread for choosing the watercooling parts you posted that you will order mcp355,swiftech xt,mcr320,compressions and etc and this list contained scythe gentle typhoon fans so why did you go with yateloon medium fans ?

Click to expand...

The answer is because i am an idiot. I had all the items in the shopping carts and i forgot to remove the fans and replace them. Then i just clicked submit when i was ready to buy everything else and realized that i just bought the fans. the good news is that fans are super cheap and even if i don't use them in this build, i can use them in the other computer that i am building as case fans.

1) should the fans be installed on top of the rad or on the bottom (meaning between the case and rad or under the rad)?

install them on top of the radiator - sucking air through it - this will give you much better performance with low-speed fans, or even better - use a push/pull arrangement with fans on both sides of the radiators for absolute best performance


2) should the fans pull air from the outside inside the case or would it be better to have the fans pull the air from inside

typically you should be pulling fresh air from outside the case for maximum performance