A tale of two fans (8-bay exhaust fan upgrades)

[jaysona]

I have a couple of 8-bay QNAP units (870 & 871) that I upgraded the rear cases exhaust fans. I decided to try two different exhaust fans models to see which are best suited for QNAP NAS enclosures, as I have a couple of more units I plan to swap out the OEM fans.

I opted for the following fans:
Noctua NF-F12
COUGAR Vortex CF-V12HP

Both are PWM, have a low dB, high m3/h airflow.

The NF-F12 were installed in the TS-870 Pro and the CF-V12HP were installed in the TVS-871, both units have the smart fan set to medium fan speed, both units have Seagate Ironwolf 8x4TB drives, the TVS-871 also has a QM2-2P-384 installed with 2x1TB 970 EVO Plus NVMe SSD.

The NF-F12 has an average speed of 1100 RPM and the CF-V12HP has an average speed of 1300 RPM, the ambient noise level between the two at a distance of ~2 meters away is indistinguishable, the spinning disks make a lot more noise that the fans do at medium rotation speed.

After one month of usage and gathering hourly data points during daily usage:
The TS-870 Pro (i7-3770s/16Gb) has an average CPU temp of 39c, system temp of 33c and HDD temps average 28c.
The TVS-871 (i7-4970s) has an average CPU temp of 35c, system temp of 31c and HDD temps average 28c.

This led me to wonder about a couple of things, the more powerful CPU had lower temps than the lower powered CPU and the TVS-871 is used to run a couple of VMs as well as plex, whereas the TS-870 Pro is mainly storage and a seedbox.

I decided try putting one CF-V12HP and NF-F12 in each unit. The CF-V12HP is in the left position, pulling air over the CPU heat pipe radiator, and the NF-F12 is in the right position, pulling air over the HDDs.

After two weeks of use, both units have essentially the same temp, variations of within 1 or 2 degrees Celsius and the sound is no different.

When the smart fan setting is set to high speed, the sound of the CF-V12HP is slightly more noticeable than the sound of the NF-F12, which is to be expected, as the speed of the CF-V12HP is about 1550 RPM and the NF-F12 is 1500 RPM.

So, the TL;DR is that if you have an 8-bay unit and are looking to replace the fans, go with one CF-V12HP in front of the heat pipe radiator and one NF-F12.

[brainchill]

Before I tear this thing apart to order fans .... I assume they are 4 pin fans?

[jaysona]

Did you look up the models on the respective manufacturer websites?

https://noctua.at/en/nf-f12-pwm/specification

Connector & pin-configuration 4-pin PWM

https://cougargaming.com/ph/products/co ... x_pwm_fan/

Connector PWM 4 pin