Question about radiators and fans

[steve252]

I'm considering my first water cooling project... i'm thinking of mounting my radiator on top of my case... my question is:

Do the fans face towards the radiator or away? Do they blow cool air onto the radiator or blow hot air away from the radiator?

I thought the blow cool air onto the radiator but systems from koolance appear to blow hot air away from the radiator...

 

[tool_462]

Either way works fine, but pulling air through the rad is optimal. For me it made 0C difference. A push/pull setup is even better though, and you can turn the fans down in speed due to the increased airflow.

 

[steve252]

thanks for the response I figured pulling air into it would be better. Push/Pull would mean fans on both sides? thats a lot of fans, i'm trying to cut down on fans, my last set up had 11 fans in it.

 

[buening]

Just think of your car's radiator. The fan is "normally" on the engine bay side of the radiator, so it pulls air through. Some people put pusher fans on when there is little clearance between the motor and the radiator, but are normally less effective. But this is on a larger scale with higher cfm. It may not make much difference with these little fans.

 

[yakyb]

it makes very little difference do what ever you think looks better however you will notice a few degrees difference if you use a shroud

 

[AdamBomb42]

From my understanding of aerodynamics, it is better to pull the air through because it creates a low pressure which help in removing the heat. This is how I have my rads setup and it work great. My idle temp floats between 26-29C with ambient temp of 23C and load temp of 38C. I'm using two Black Ice 120GTS Stealth X-Flow and low CFM fans. One in the front and one in the back.

 

[The_Interloper]

Koolance setups blow hot air away from the radiator because when the hot air is blowed back into the case, the overall system temps rise.

 

[jitpublisher]

The reason the fan is on the back side of a car radiator is because as the car starts moving, the fan basically is unimportant. Above 30 mph, there is more air coming into the radiator from the car movement than the fan will pull. It the fan is placed in front, it becomes an obstruction rather than being a benefit. If you notice, todays fans are most always electric, and at road speed, they completely turn off. Years ago, they had heat sensitive clutches, so as they cooled down, the fans would be released from the shaft suppling power to them and basically freewheel on the shaft. This also saves on horsepower and gas. It takes a lot of power to run a automobile fan. People who put fans in front of radiators are street cruisers, hot engines that need all the help they can get while cruising around town at low speed, and as you mentioned, because of space limitations behind the radiator.
For these reasons an auto having the fans in front is not optimum.

 

[steve252]

Thanks for your replies i'm going to take everything you guys said into consideration!

 

[gudodayn]

I'm using two Black Ice 120GTS Stealth X-Flow and low CFM fans. One in the front and one in the back.

Just wondering with your two radiators, where exactly do you have them setup? I'm only asking because I am thinking of adding another radiator to my exsisting setup, current loop is RESERVOIR > PUMP > CPU BLOCK > RADIATOR then back to RESEROIR

I am not sure if I should go with.........

1. RESERVOIR > PUMP > CPU BLOCK > 1st RADIATOR (12cm) > 2nd RADIATOR (12cm) then back to RESEROIR

or

2. RESERVOIR > PUMP > 1st RADIATOR (12cm) > CPU BLOCK > 2nd RADIATOR (12cm) then back to RESEROIR

And of course, were there any temperature differences before and after adding the second radiator.....provided that you started with one radiator only....

 

[AdamBomb42]

I'll take some pics when I get home tonight and show them to you.

 

[gudodayn]

I'll take some pics when I get home tonight and show them to you.

Alright.............thanks
So, was your setup with one radiator only, initially?
If so, did it make a difference when you added the second radiator into the loop?