140mm Fans in 120mm Mounts? Explanation Needed

[PantherTyler]

Ok so i'm planning out my PC build and I've got basically everything planned out and priced out just now i'm looking at fans for better cooling for my build. I'm picked a Corsair 750D case and I had a possibly stupid question to ask. I was looking at a comprehensive list of 140mm fans because i wanted to see if I could get better fans that had higher cfm for the top (before I get my Swiftech h240x cooler) and I came across a few products that said they were 140mm fans with 120mm mounts. Since the 750D case can fit two 140mm fans or three 120mm fans on the top, could I then technically mount three 140mm fans that have the 120mm mounts?

Heres the link to what i'm referring to: http://www.frozencpu.com/products/21851/fan-1273/Phanteks_140mm_x_25mm_UFB_Bearing_PWM_Fan_-_White_Frame_White_Blade_PH-F140HP-WT_120mm_Mount_Pattern_.html?tl=g36c365s1507


Also the case comes stock with A140L High Airflow Fans (2 front, 1 back), would the fan listed above be a better replacement?

I'm very new to the cooling world of PC, actually just new to PC building in general so I'm not sure where to look to find high airflow or static pressure fans.

 

[clutchc]

If the top accepts only 2 x 140mm fans, then I can't see any way it will fit 3 no matter what kind of hole layout the fan housings have.

Btw, I think FrozenPC is in the midst of closing its doors. Although this seems to say it might hang in there for awhile.
http://www.maximumpc.com/frozencpu_running_skeleton_crew_vows_stay_business
Still, if you have to return something down the road a ways...

 

[PantherTyler]

What i'm confused with is if its a 140mm fan, but it has 120mm mounts does that mean it mounts on the 120mm locations meaning couldn't i mount three of these fans on the top where normally three normal 120mm would go?

 

[synphul]

If the case has room for 3 120mm's or 2 140mm's then those are the mounting options for the fans in terms of space. A 140mm fan can be square with mounting holes at the 4 corners and be 140mm mounting or it can be round/octagonal shaped with small tabs or ears that have mounting holes that match 120mm hole spacing. It's still a 140mm fan though. The circular portion of the fan's shroud is still the same size, all they've done is removed the exterior framework in order to make it line up with 120mm holes.

Something to consider, it depends on the top of the case. Looking at the top of the 750d, it would be best to avoid 140mm fans with 120mm mounting. Some cases have slots where the fan screws can be loosened and the fan shifted some one way or the other. The 120mm top mount holes on the 750d aren't slotted, they're strictly holes. Meaning if you try to put 2x 140mm fans using the 120mm mount holes next to each other the fans won't fit. The shroud of the 2 fans will hit one another and won't line up. Either get 2 or 3 120mm's or get the 2 140mm's with standard mounting. I think 2 120's or 140's would be plenty, the 3rd 120mm fan will be so far forward it will basically be inside the top 5.25" drive bay and probably won't add a whole lot to the case cooling.

 

[PantherTyler]

Would you recommend two 120mm 241cfm fans at the front or two 158cfm 140mm in the front?

 

[synphul]

Did I read that right, 241cfm 120's and 158cfm 140's? What sort of fans are you putting on there, noctua ippc's or deltas? Either way, the 140's will probably be a bit quieter. Not sure if sound is a concern for you (front fans are typically closer to the user so will seem louder). Beyond that, higher static pressure in the front would be better, not sure which (probably the 120's) have higher static pressure. That is if you're pushing air past the hard drive cage(s). So long as you have decent airflow (no dead spots) and frequently exchanging the case air, it won't be of much benefit to go overboard. It's still cooling with ambient air so at some point there will be diminishing returns.

Having a 140mm for rear exhaust, 2x 120/140mm on the top and 2x 120/140mm should be more than plenty for good ventilation. Just keep in mind if those cfm ratings you mentioned are correct, this pc is going to sound like a jet engine. For reference, the coolermaster jetflo 120's have pretty high airflow at 95cfm - look up one on youtube and have a listen to it at 12v. About the only thing worse are deltas (for noise, they have great airflow). There are quite a few fan noise comparison vids on youtube, it would at least give you an idea of what to expect. Even if you can't match the sound of the vid playing on your pc to real world, if there are multiple fans reviewed you can get a rough idea one compared to the other.

 

[Namdhda]

If you can fit 3 120s or 2 140s on the top, I've got a real nice idea for you. Get yourself an aio water cooler! Corsair makes a 280mm radiator (2 140s next to each other), and thermaltake's water 3.0 ultimate is a 360mm radiator (3 120s next to each other). Either of these will obviously cool the crap out of your cpu, but more importantly they will add a healthy amount of airflow to your tower! Do note that the 360mm radiator costs you your top drive bay, unless you put in a usb hub or something that only has a small pcb and some wires that you can route under/beside/elsewhere.