Radiator/Fan placement...

[ZenDragon]

Due to the usually smaller size and shape of the cases I've used in the past I have generally run my AIO coolers with the radiators on the top or in the case of my 250D on the side, primarily because I couldn't fit them in the front. I typically had the fans inside the radiator bowing out of the case. I recently purchased a Corsair 280X, and out of habit I just mounted the radiator on the top with the fans inside blowing up though the radiator. However, after putting everything together and realizing I now having the room to choose I went looking for some opinions on the differences and saw a video on youtube of a guy who saw a 10 degree difference in the temp of the CPU with the radiator in the front and behind the fans.

So my question for you all (before I got tearing apart my build again) is, would I still see that benefit if I simply mounted the radiator to the top with the case with fans on the top of the radiator blowing down? With the front fans still blowing towards the back of the case of course. At that point all of the fans would be blowing IN to the case with no exhaust fans, so would it then be necessary to install an exhaust fan somewhere? Anybody have a 280x and have some opinions or experience with cooling in this case? I've already noticed my temps to be a little on the warm side, nothing I would be concerned about but overall warmer than I would have expected in general.

 

[Hakaba]

So... In my mind, I would pull fresh air from outside the case over the radiator and then let the air get pushed out or sucked out. My logic, the air is cooler outside of your case and will affect the cooling performance of the radiator. However, I am unsure how well your case vents air in a positive air setup.

Is your GPU air cooled? Ideally you would put the rad on the front and pull in air/exhaust out the top. But your GPU will in take pre heated air, not sure if putting a fan at the bottom as I take will help the increase of temps.

 

[ZenDragon]

That was my thought as well. This particular case has a full glass panel side with a small gap between the panel and the case, and a generous vent in the rear which doesn't look like it was intended for any fans. I'm not sure if that would help the "positive air" effect much, or hurt it overall. The marketing materials for this case show the air flow coming in the front and out the top, hence why I did it this way as it seemed like that was the intention. A possible 10 degree different in CPU temps is pretty significant, however that test was on a different case, hence why I am asking if anybody has done any experimenting with this case specifically.

It seems to me mounting the radiator in the front would hurt the overall ambient temp under load as you would be blowing warm air into the case, but would keep CPU temps lower for the reason you stated. Perhaps simply mounting a couple fans to the bottom and leaving the radiator as is would help, as it would be increasing the overall level of cooler air entering the case to make up for the warmer air blowing through the radiator for the CPU? Alternatively, perhaps moving the radiator to the front while still adding some fans to the bottom would give the best of both worlds? While I may have just talked myself into a solution, I'd still be interested to hear what other 280x owners have experienced.

Also, I did think about mounting the radiator to the bottom. Which is a possibility but it would place the radiator right next to the video card fans, and seems like it would impede air flow to the GPU. I would imagine overall the benefit to the CPU would be the same as mounting it to the front.

I'm so used to using Mini-ITX boards and cases with limited cooling options I just don't know what to do with myself with all this extra room! haha!