How much heat does a 3.5 hdd make?
Im thinkin about gettin a Cosair air 240 and some reviewers suggested installing a fan on the back section for the hdds. How much heat do they actually produce and is it really worth putting a fan in when its going to be mostly full of cables?
Hdds by themselves usually don't put out much heat at all. That said, they are also stuck in areas of the case with either little to no airflow and/or are the recipient of ambient heat especially from a powerful gpu. Basically this means they just sit and bake. Having even a small amount of airflow across the hdd is a blessing and in more than a few cases this is accomplished by a larger or second intake fan, so is not an issue.
If you are worried about it, use a program like speccy from piriform, its small, easy and free, yet has tons of decent info, including hdd temps. Hdd temps should be @10° above ambient, then push the gpu hard for 15 mins or so, it being the largest heat source, if the hdd temps climb past 20° above ambient then add some airflow, otherwise it's not an issue.