Air in or out?
 

I bought two 120mm fans for my Alienware system. It has a spot on top of the case that allows extra fans to be installed. I had my buddy Killswitch come over and he suggested installing them to allow air intake rather than exhaust. The case design would lead anyone to think these fans should exhaust. However, having the fans reversed lowered my Proc temps by 10 to 15c when playing games.The radiator fan for the liquid cooling is still set up to exhahst air, but Killswitch will come over again and flip that one over as well. It appears the more cool air in is better than fans blowing out.At least on Alienware Area 51 designed cases.Just thought I would mention this for Alienware owners. I know there are a few here. Take care all.

it's called positive air pressure. you want more airflow going in then you have going out.

YouTube - Fortress FT01 PC case with positive air pressure part 2
YouTube - Sugo SG03 SFF case positive air pressure demonstration
yup always

Lemmy get this right. your going to flip the fan on the Rad? nonononono bad bad idea. Your not wrong in wanting alot of "cool" air in the pc, but the purpose of the RAD is to HEAT the air, The fan on that rad is in exhaust position because you want to get RID OF the hot air, not put it back INTO the case.

Thanks all. Very informative. I'll talk to Killswitch and maybe we will re-think this.

Am I reading you correctly? The Rad circulates water that is cooled by outside air being drawn IN through the rad .As my rig is configured now,the air is being exhausted from inside the comp. case and out through the radiator. There is no cool air going into the Rad as the air going through it comes from inside the case. I don't know if I'm explaining this right but I think you grt the picture.Also, why would you have a Radiator to Heat the air? Am I not understanding any of this? Thanks.

The rad is cooled by the air inside the case, which is blown by the exhaust fan through the rad and out the back of the computer.

the cpu gets hot, the waterblock absorbs the heat, the water flows through the waterblock absorbing the heat from it. the heat travels through the pipes into the radiator, the radiator has very very thin fins with water tubes in between, these fins absorb the heat from the water. the exhaust fan blows air through the radiator across the fins absorbing the heat and then flows away from the computer, completing the heat dissipation cycle.

Using cooler air is more efficient than warmer air, but it is all relative. The air from inside your case isnt sufficiently warm enough to cause enough of a detrimental effect to the efficiency of the radiator.

For example. when you use air that is at room temperature to cool the radiator your cooling system might be at 50°C, when you use warmer air from inside your case, the water temperature may rise a couple of degrees to say... 52°C. That is not to say that your CPU is going to benifit much from the 2°C cooler water, as in reality your cpu, unless you are EXTREME overclocking will likely remain at whatever temperature it was running at in either instance.

The reason that your computer is setup the way it is, using warmer case exhaust air, Is more of design efficiency than cooling system efficiency. If they were to design your system to use cooler ambient air, they would have to mount the radiator away from the case, making the case bulky and harder to handle and much more expensive.

As it is, the design is efficient. the case needs to exhaust air anyway, and has a fan blowing out. Mounting the rad in front of the blowing air utilizes air from a fan that already has to exist, allowing the radiator to mount flush with the case and reducing the amount of materials needed to build the system and keeping the computer looking sleek and professional.

That point aside you still want at least one exhaust fan or somewhere for the warm air to vent.

I have a 92m exhaust fan at the rear of the computer. That leaves it with two top mounted 120mm intake fans,the 120mm exhaust Rad fan, also mounted on top of the case, the PCI front air intake fan and of course the exhaust fans on the Nvidia cards. Sound about right?

yep, i'd leave it just like that