780t Case Fan Configuration Help

Hi,

 

Hoping someone can help me.

 

Im planning on purchasing the 780T and was planning on using 2 x 140mm fans at the front (intake), 2 x 120mm fans at the bottom (intake), 1 x 140mm fan at the back (exhaust) and 2 x 140mm fans at the top connected to a AIO CPU water cooler (exhaust).

 

So my questions are:

- should i switch out any of the 2 x 140mm for 3 x 120mm?

- which of the fans should be AF and which should be SP?

- and finally which of the fans should be intake and which should be exhaust?

 

Thanks

I would not swap the 140 fans for 120 fans, I feel that the 140 fans will probably push through a similar volume of air as the 120's but at a lower (and quieter) speed

The case fans should be AF (Air Flow) and the radiator fans SP(Staitic Pressure), although, if you are feeling particularly flush, you could try the new ML fans in any position.

The way that you have them looks fine to me. You may not need both (or either) of the fans in the bottom, as long as the other fans supply a good flow of air through your case.

 

This is only my opinion, I'm sure that others will disagree, you can always try it as you want and experiment.

This all sounds good to me and that is the way I would set it up.

 

Front panel: 120x3 vs 2x140 - With most moderate speed 120mm fans, you can get an airflow volume advantage with 120x3. However, specifically for the 780T, I don't see any reason to do this unless you have one or more of the following: multi-gpu set-up, a 1st generation m.2 drive that is very temperature sensitive, or a lot of drives that need active cooling. If you do decide you need 3x120, I would not opt for the AF120 style. You would be better served with a hybrid style in between the SP/AF dichotomy with moderate angle and width on the blades. This would give you a more focused air stream (targeting the above hardware), yet still cover the entire case with a good amount of air. Since the case will already come with 2xAF140's there, I don't see any reason to change it out until it has proven ineffective. 2 AF 140s@900 will be quieter than 3x120@1300-1500 rpm (an equivalent amount of air). You will also have bottom fans supplementing the intake volume, so air volume alone is not a good enough reason to buy 3 120mm fans.

 

The rear should also come with 1 AF140 (grey). Nothing wrong with the fan, but if you want to change it out for stylistic reasons, the ringed AF140 is an easy replacement, although you could also give some consideration to the below.

 

The one set of fans I would change is the SP140L that come with the H110i and H115i (if you are buying a Corsair 280mm). They tend to drone quite a lot in the inverted position. Lots more choices in 140mm radiator fans than there used to be and the ML140 is an easy and satisfying replacement. To that end, you can match your rear exhaust fan to the top radiator fans, if that matters to you. It likely will have no impact on actual case temperatures and something like a ML140 is a multi-purpose fan.

 

Bottom - 2xAF120s would be fine, however I think my preference would be for a hybrid of SP type flat blade. Generally, these fans will run low speed, likely have a dust screen in their way, and mostly serve a supplemental intake or direct cooling on part of the board. I use some hybrid style 140's on the bottom of my 740. They turn slow and steady and keep my m.2 and PCH temps at laughably low levels. At low fan speed, the flatter style blade is more effective for these purposes.

Thanks for the help, when you say hybrid fans are you referring to the ML and HD fan series? Which can be used as both SP and AF fans?

Thanks for the help, when you say hybrid fans are you referring to the ML and HD fan series? Which can be used as both SP and AF fans?

 

Correct. The classic SP120 (ringed, not RGB) and AF120 are the opposite ends of the blade spectrum. An AF120/140 has 9-11 thin, steeply raked blades. That design will move more air, with less noise than a flat and broad blade. However, its air flow pattern will be wide and when faced with resistance (like an dust filter or radiator) the fan will be more adversely affected, especially at low speeds. The SP120 with its wide and flat blade will move less air by comparison, but in return has a focused air stream better for direct cooling of hardware or when faced with large resistance like radiators.

 

A 'hybrid' is just something in between the two ends. Most 120mm fans on the market are in the middle and when looking at 140mm fans, you are not going to find a blade as thick as the SP120. I suspect at that size the additional mass becomes a problem, but regardless a radiator designed 140mm fan will be hybrid-like, with medium rake and 6-7 blades.

 

There seems to be a return to more medium style designs as of late. While a flat, heavy static pressure fan will do better at the lowest speeds and a AF style fan can overcome resistance at high speeds, the hybrid of the two is often the best in the medium speed range where most people spend all of their fan time. This makes it an effective compromise for a lot of uses. Most people do not want to run their fans at maximum, but are willing to turn them up a little when under load. There still are some specific uses for the two archetypes. If you wanted a low speed fan for direct cooling, flat and broad is what you want. High airflow with the least amount of noise possible? AF style. The wide flow pattern of AF fan can also be useful for exhaust duty, since the draw is wide on both sides of the fan. Also, if you want to split hairs, an AF140 is likely going be quieter and move slightly more air at 700 rpm on the front intake than a fan with a flatter blade. You are getting 3 AF140's with the case. I don't see any reason not to use them. If you decide something is not ideal, you will have a basis point of comparison. The only place where you might want something different is in the bottom. Those are generally going to be slow turning and I am not sure an AF120x2 would be my first choice, but they would also be fine at medium speeds.

Thanks for all the help, this was extremely helpful.