Question Optimal fans/placement in P400A Non-RGB

[Mbaier]

So I am getting a Phanteks P400A case without the fancy RGB fans. I want to add another 1-2 120mm fans to the case. I don't need fans with lights, just looking for something quiet-ish that moves some air and is not too expensive. I am in the US and have heard good things about Noctua. Thanks!

 

[Mbaier]

If it helps at all, this is the build so far.

PCPartPicker Part List

Type|Item|Price
:----|:----|:----
CPU | AMD Ryzen 5 2600X 3.6 GHz 6-Core Processor | Purchased For $115.00
Motherboard | MSI X470 GAMING PLUS ATX AM4 Motherboard | Purchased For $110.00
Memory | Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-3200 Memory | Purchased For $71.00
Storage | Intel 660p Series 512 GB M.2-2280 NVME Solid State Drive | Purchased For $49.99
Storage | Western Digital BLACK SERIES 1 TB 3.5" 7200RPM Internal Hard Drive | Purchased For $0.00
Video Card | MSI Radeon RX 550 - 512 4 GB AERO ITX OC Video Card | Purchased For $0.00
Case | Phanteks Eclipse P400A ATX Mid Tower Case | $72.98 @ Newegg
Power Supply | Corsair RM (2019) 650 W 80+ Gold Certified Fully Modular ATX Power Supply | $84.98 @ Newegg
| Prices include shipping, taxes, rebates, and discounts |
| Total (before mail-in rebates) | $518.95
| Mail-in rebates | -$15.00
| Total | $503.95
| Generated by PCPartPicker 2019-09-13 09:48 EDT-0400 |

 

[Paperdoc]

Just to be sure I got this right, you have the Phanteks Eclipse P400 Black case, Model PH-EC400ATG_BK, which includes two 120mm black front case fans with no RGB lights. Please confirm, I believe each of those fans is a 3-pin model. That is, the cable from the fan has THREE wires, ending in a standard fan connector with THREE holes. I expect you are supposed to connect those to 3-pin headers inside the case top near where it has a fan control button. Those will be pre-installed as intake fans, and the case does not come with any pre-installled exhaust fans. However, it does have open locations for about four more fans. One more 120mm fan can be installed in the front, one can be installed as exhaust at the rear, and two could be installed at the top, most likely as exhaust. I gather you are NOT planning on getting an AIO liquid cooler system that adds a rad and fans; you will simply use the air cooler fan and heatsink provided with the CPU from AMD.

If you were to add just two fans, one certainly should go to the rear as exhaust. The second could go to one of the top locations, also as exhaust. This provides two intakes and two exhausts, a balance in fan count. However, the front intake fans have dust filters in front of them as the SHOULD (remember to check and clean them sometimes) that reduce their air flow slightly, so the net result in terms of actual air pressure inside the case (a result of air FLOW not matching) would be a slight negative internal pressure. You may consider that not important, and it's not a big deal. Personally I prefer a slight positive internal air pressure so that any air leakage at small gaps is OUTWARD, and does not allow dusty air to sneak in. To do that you might consider installing a third front intake fan.

Another way to accomplish that pressure balance might be to do a different fan re-location. Move the two Phanteks 120mm fans to the rear and top locations. Then replace them in the two front locations with 140mm new models. Typically for the same fan control signals from the mobo headers, the 140mm fans create more airflow that the 120's do, so that would produce the small positive pressure design I personally prefer.

Just a note here on fan speed control. I gather the two fans in the case as supplied are connected to a manual fan speed control button on the case top. But I also presume that those fans actually have wires and connectors from them that do fit onto standard mobo SYS_FAN headers as an alternative. If you reconnect them that way, the mobo header's default automatic fan control system can control those fans' speeds for you with no attention from you, rather than allowing / requiring that YOU decide when to change their speed via the manual button. Your choice.

So, which fans? You have heard of Noctua fans, and I do like and use them. As a general rule they produce higher air flows at good backpressure ratings with lower noise than many competitors' fans, and their reputation for long life seems well deserved. However, they are often a bit more expensive. Further, their main fan line is a light brown frame colour with dark brown blades, and many do not like that scheme. They do have another line that is all dark greys, which might suit your plan. For this case ventilation application you do not need fans designed for high backpresssure (for heatsinks and rads), so concentrate on air flow and noise specs. See their master fan list here

https://noctua.at/en/products/fan

and you can click on any model number to get detailed specs. For your purposes, I suggest you consider these. In most cases I'll list the THREE-pin model similar to what you already have (my notes further down), but you will see matching 4-pin models on the same Noctua page

Their common 2-tone brown 120 mm models
NF-A12x25 FLX
NF-S12A FLX

Their related 2-tone grey 120 mm models
NF-P12 redux-1300
NF-S12B redux-1200

A 140mm 2-tone brown
NF-A14 FLX

A 140mm 2-tone grey
NF-P14s redux-1200

3-pin fans and 4-pin fans require that the mobo fan header use different methods of controlling their speeds. That is what the MODE option in header configuration is about. Use the older DC Mode for 3-pin fans, and the newer PWM Mode for 4-pin fans. Your mobo has four SYS_FAN headers for case fans, and each of them can be configured for either Mode, but they come pre-configured to DC Mode. So if you buy 4-pin fans, the header you plug them into needs its Mode setting adjusted.

Each mobo fan header can supply up to 1.0 A current total to all the fans connected to it, and most of these fans use at max 0.15A, so you CAN use a SPLITTER to connect two to four fans to a single header. For example, you could connect all your front fans to a single header, etc. BUT if you choose to do that, create groups based on the fan TYPE (3-pin or 4-pin) because all of the fans on one Splitter will receive the SAME signals from their common header. So you can configure different headers for use with a group of 3-pin fans or a group of 4-pin fans. To keep that even simpler, I highlighted the 3-pin styles above. If you were to buy only 3-pin fans, then ALL of your case fans would be of that type and creating groups would be a non-issue.

A small item to be aware of. Any mobo header can accept the speed signal coming back to it from only ONE fan. So if you use a Splitter to group some together, it will send back to the mobo only ONE of its fans' speeds and ignore the rest. This has NO impact on ability to control the fan speeds, but it does mean you cannot "see" the speed of the fans whose signals are ignored, and the mobo header cannot monitor those fans for FAILURE. So from time to time YOU should check to be sure all the fans are still working.

 

[Mbaier]

Wow, thank you for your long, thorough response.

That is the correct case. It comes with two 120mm fans. I have seen comments that the RGB fans that come with the other version of the case are 3 pin fans but have not seen comments on this version. Pictures of the case show one fan in the middle position in the front and one on the back.

I was not intending to use an AIO cooler and was going to use the stock AMD CPU cooler.

I was intending to either move the stock front fan to the top and get two or three new fans for the front or just add a fan to the front.

I guess my first step should be looking at the case when it arrives on monday and figure out how many pins the fans have...