Radiator and fan size questions

I'm not ready to jump on anything yet, but I'm looking at the new NZXT Switch 810 for a possible build in the future. I have two main questions.

1. As the Switch 810 can fit either a 120.3 or a 140.3 radiator, is there any reason to not go for a 140.3? I have no problem with spending the extra money for a 140 rad.
   
2. Assuming I go with a 140.3 rad, I'm not sure which fan setup I would prefer: 140mm Yate Loons or 120mm Gentle Typhoons using a plastic fan adapter. Is there a noticeable disadvantage to using 120mm fans on a 140mm radiator? If it matters, I'd probably be doing push/pull with either option and have them on a fan controller.

Also note that this isn't for my current build and will be used with something like a 3770K Ivy Bridge and 7950/660Ti (or whatever they end up calling it) in a single loop.

The major downside to 140mm rads is the 140mm fan selection, throw 120mm fans on there and call it a day IMO

The reason some people shy from 140mm radiators is because they either don't fit in their case, or they are much harder to find fans for.

I'll say this about using 120mm fans on your 140mm radiator: you've got to remember we're talking diameter here, so you may not think 20mm sounds like a lot, but it's the outside 20mm of the fan that you're adding, so the actual area is pretty big. There's a pretty big difference in air flow between a 120mm fan and 140mm fan. For example, I was also looking at Yate Loons (ended up buying them), and the 120mm high speed fans put out 88 CFM and the 140mm high speed fans put out 140 cfm. That's a 60% increase in air moved just by that outside 20mm being added.

If you're using low fpi radiators that don't require a lot of airflow you'll probably be fine with 120mm fans, but I wouldn't do that for a radiator with high fpi that requires air flow.

In comparison a 3x140mm radiator is actually larger in surface area than a 4x120mm radiator. That's why so much more air is moved by a 140mm fan. The actual area you're adding is substantial even though 20mm doesn't sound like a lot.

If you can fit 140mm radiators and don't mind the added expense that's probably the route I'd go. Well, that is the route I went where I could

thebski said:

The reason some people shy from 140mm radiators is because they either don't fit in their case, or they are much harder to find fans for.

I'll say this about using 120mm fans on your 140mm radiator: you've got to remember we're talking diameter here, so you may not think 20mm sounds like a lot, but it's the outside 20mm of the fan that you're adding, so the actual area is pretty big. There's a pretty big difference in air flow between a 120mm fan and 140mm fan. For example, I was also looking at Yate Loons (ended up buying them), and the 120mm high speed fans put out 88 CFM and the 140mm high speed fans put out 140 cfm. That's a 60% increase in air moved just by that outside 20mm being added.

In comparison a 3x140mm radiator is actually larger in surface area than a 4x120mm radiator. That's why so much more air is moved by a 140mm fan. The actual area you're added is substantial even though 20mm doesn't sound like a lot.

If you can fit 140mm radiators and don't mind the added expense that's probably the route I'd go. Well, that is the route I went where I could

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The only downside I see to the 140mm fans is that for some reason I vastly prefer GTs to Yate Loons. Would you say the advantage gained from having 140mm fans would make up for any (possibly negligible) drop going from GTs to Yate Loons?

Yes and no, yates will have them on max flow, but there aren't many good 140mm fans with solid static pressure, so pushing air through a rad will be harder. This is due to the fact that the way 140mm fans are being made right now is using the motors from 120mm fans, where they should be shifting to a larger motor-hub and a higher torque motor to push air better, instead they use the old motors they have and the fans do not fare well in the face of restriction