Beta Orionis – Part IV

Build Log:

First order of business for the build was getting it out of the 750D case and into the Zalman.

That started with getting fans put back in, as I originally pulled all the fans out of the Zalman to max out the fan space in the 750D. I installed three 140mm fans where I could, two in the top for exhaust and one in the front for, obviously, intake. I also added two 120mm fans at the bottom and rear, both as intakes. The Mountain Mods fan bracket would be going in the Zalman case, to be used for mounting the radiator for the Corsair H60 if I could make it fit. If not, I would be putting that in the rear 120mm fan position and just have a fan on the fan mount.

Then there was getting the power supply installed as well. The spare GS800 will be powering things for the time being. When the CX750M comes back from Corsair, it’ll tag out the GS800.

That was Thursday night. The package came on Friday. My wife’s birthday. We went out for dinner, so there wasn’t much use in trying to move everything over, as I wouldn’t have a lot of time to function. Plus she collapsed into bed not long after getting home from the restaurant, and I didn’t want to disturb her.

With Saturday came a full-time shift for my wife, so plenty of time for me to move everything into the Zalman case and start with the test fits to find out if I was out of my mind with doing a single 140mm and single 120mm radiator in the front.

Test fit #1

First was the test fit on the 140mm radiator in the front, just to make sure it’ll fit the way I was originally thinking. It does.

Now this radiator is actually going to go over the bottom 140mm fan. I had it over the top fan to make sure it would clear the rivets that are a couple millimeters above it. But that is the intended orientation.

One question still outstanding is whether I can fit two 140mm radiators side by side in the configuration shown above. I’m currently under the assumption that I cannot. I know from this test fit that at least one will fit where I want it. And I know from doing a test with the short screws I bought – #6-32 x 1/2″ – that it will raise the Bitfenix fans up by about a millimeter or two, basically pushing the fan clear of any potential interference. This means that if I use a 120mm radiator in the position the picture currently shows the 140mm that it’ll fit without any problem.

The only concern is just that I’d probably have to pack out the radiator with some washers to ensure the screws will not go too far through and risk puncturing the radiator, or just use the XSPC radiator gasket.

So my next radiator order is actually two more single-fan radiators: a 120mm and a 140mm radiator. If the 140mm fits where I hope it will, then the 120mm will either go in the rear mount position, or I may add it to Absinthe. If it won’t fit, then the 140mm will likely get returned, unless test fitting it in the fan position on the back of the case turns out well.

Test fit #2

Now for the 240mm radiator I bought. I had no reason to believe it wouldn’t fit. My concern was how it’d fit with the 140mm radiator in the lower position. Everything told me that it should work without any problem, but I wanted to be certain, as these test fits govern my future planning.

This was also part of my concern: would the cable for the lighting fit between the fans when mounted on the radiator. As can be clearly seen, the answer is Yes.

And with the 140mm radiator mounted in the lower position, there is little concern here as well with the fit. As you can see I have the fans mounted for a pull configuration as opposed to a push configuration. With low FPI radiators and lower RPM fans, there is little difference between the two. With how the radiator is mounted in the 750D, you can see there is a small gap with some vent holes exposed. I’ll need to think of something I can do to cover that. Just not sure what at this point.

But this still leaves outstanding the question of whether a second 140mm radiator would fit above where it is mounted here. I know I have plenty of clearance for a 120mm radiator and I’ve been leaning toward just buying the 120mm radiator and foregoing the possibility a 140mm radiator would fit.

So let’s do a little math to find out if it’ll be worth the trouble, or whether I should just go for something that I know is guaranteed. Now each 120mm of radiator space provides for 14,400mm2 of surface area. Each 140mm of radiator space provides for 19,600mm2 of surface area. This means that the two configurations I’m considering each provide for:

5x120mm + 2x140mm = 111,200mm2 surface area
6x120mm + 1x140mm = 106,000mm2 surface area

A difference of 5,200mm2 of surface area. But what’s that compared to the overall surface area of the smaller configuration? Only a 4.9% improvement. I think I’ll go with what’s guaranteed and save myself the trouble.


Now some would probably question why I’m going through the trouble of trying to fit two single-fan mounts on the front. And the answer is quite simple: to maximize radiator capacity.

If I put a 240mm or 280mm radiator on the front, I can only put a single 120mm radiator on the bottom, meaning maximizing radiator space would require putting another 120mm or 140mm radiator on the back. If that front radiator is a 280mm, I also lose a 120mm fan mount at the bottom, as the 280mm radiator would interfere.

If I went with the maximum size supported, that would mean a triple 120mm in the top, a single 120mm in the bottom, a dual 140mm in the front and single 140mm in the back. That’s 4x120mm and 3x140mm, for a total surface area of 116,400mm2, a 9.8% increase in surface area over what I have planned currently. But, again, I lose a 120mm fan mount position doing that. I don’t consider that a good trade-off.

Plus with my current plan, if I add another 120mm radiator to the back, I increase the total surface area to 120,400mm2, a 3.5% improvement. If I make it a 140mm radiator, that goes up to 125,600mm2, a 7.9% improvement in surface area. Both obviously surpass in surface area what would arguably be a less complicated solution. So my current plan leaves me with the option of that additional level of expansion if I want to use it. It’s also why the 240mm radiator is the ST30 instead of something wider like the XT45, giving room to mount two single-fan radiators on the front.

It’s an unusual setup, and I look forward to planning out the loop. Ideally we would have side-flow radiators that can flow similar to what I’ve got planned here, only as one unit. The closest I’ve found to that is the Aquacomputer Airplex Modularity System. But the single 140mm fan option is 146mm wide, making it useless for my needs. Plus it’s three times the cost of the XSPC radiator.

Next phase

So that’s it for this iteration. The next order will be the two remaining radiators: the AlphaCool ST30 360mm and XSPC EX120. This will allow me to have all the radiators mounted for test fits, along with starting some of the planning on the loop.

The drain is currently planned to come off a T-fitting on the lower radiator. The water blocks are in a fixed location, while the pump and reservoir will be mounted atop the 120mm fan closes to the fittings on the bottom radiator. But having the other radiators will allow me to finish the test fits and start determining how the loop will be tubed up.