Recently tried installing an h100, however the eps/eatx 12v input on the very top of the board is obstructed by the 120x120x25mm stock fans. I'm considering buying yate loon 120x120x20mm fans and using those instead and see if this solves the problem.
I'm wondering if 20mm fans should be strong enough to push air out of my case through the rad (I have a 400r, and im pulling air from the front of my case).
getting a ruler and some time with the rig off will yield results to how much clearance you have from mobo header to rad.
^Measuring it yourself is the only way to be sure it'll actually fit.
It sounds like you need a different case.
I can't quite picture your problem though.
My understanding is that the setup SHOULD go like this:
1) H100 radiator/fan unit mounts below the TOP of the case
2) normal 120mm case fan is at the TOP-REAR
3) Power Supply is at the bottom.
So, again, what is the problem?
He's mounting the H100 in the top with the 2x120mm fans attached to the bottom of the H100. The overhang is blocking the CPU Power connector (8 pin)
Unfortunately this isn't an option since I have cats that like to jump around on stuff (mounting the fans outside of the case).
Corsair 400r and h100 is "supposed" to work fine together. A lot of the issues of clearance are with the certain mobo brands sticking the 8-pin on the very top of the board, which conflicts with the fans (I know gigabyte has the 8 pin lower, and on some boards off to the side.
Gonna try the 20mm fans and see if that solves the problem.
I don't believe he's asking whether the 20mm fans will fit, but whether they will push enough air.
They will not.
The stock H100 fans move considerable CFM, and more importantly, they have very high static pressure.
No 20mm fan will be able to come close to matching those specs. There's no sense in running the H100 if you can't push (or pull) enough air through it to draw the heat off.
Although the 400r definitely is set up nicely to fit an H100 (at least as smaller cases go), the mobo is a deterrent in this instance.
(I have the same board in the much larger 650d, and though the H100 is an easy fit, even with the P8Z68, adding an extra set of fans for push-pull runs into the same clearance issues, and the need for a little installation creativity.)
Fans on top is probably your best setup. Don't worry about your cats; just get some fan grills for the tops of the external fans: something with openings small enough to keep kitty's toes out, but not so small as to be restrictive.
And a dremel to pass the wires through?? C'mon... it's not too tough to finesse it a little better than that. (Why not just punch through with a hammer and a screwdriver, if you're going that route?)
Remove the plugs from the fan cables, pass the cable ends through a couple of the extra holes (the ones provided for 140mm fans) and reattach the plugs. (Push the retainers back, and the terminals/wires slide right out of the plugs.)
Scrap the idea of using those skinny fans, though. They aren't up to the job.