Fan choices and decoupling
If noise is of importance the fan you choose can make a big difference. Choosing a higher quality fan is much more about noise then it is how effective it is at removing heat!
For this build I have actually deviated from my all-time favorite Noctua! But why do I always go for Noctua?
Noctua, built to last
Next to thermals and noise there is another aspect about fans that isn’t often talked about and that is their longevity. I’ve used many different brands of fans over the years but in the recent 10 years or so I have always chosen Noctua. Yes they are expensive but they are excellent all-round, not just in one category.
I’ve had different brand fans before which which had good airflow for instance or didn’t make too much noise, but very often their longevity would start to become an issue over a course of just 2 or 3 years. They start to make more noise and thus thermals and noise would get worse! Some even just locked up completely all together.
So while you pay a lot of a Noctua fan in my opinion if you are going to be running these for an extended period of time, especially 24/7 like in a home server application they are well worth the money in just knowing that fan will still perform the same 5 years from now as it did when you installed it.
Still making a different choice? Phanteks T30!
Yes, I also love to experiment! I have tested this build using a Noctua NF-A12x25 PWM and that of course works and performs just fine. But I’ve been intrigued with the Phanteks T30 fans, these are 30mm thick instead of 25mm allowing them to move a bit of extra air! Other then that it takes some very very strong queues from Noctua including the same type of material and using a high quality, motor, etc.
The Phanteks fan also has a switch allowing you to set it to silent, normal or performance. I keep the switch set to normal since I don’t need a jet turbo fan to cool the CPU we’re using.
The Phanteks T30 fit perfectly on the included CPU heatsink from minisforum the only change it requires is using 30mm M2.5 screws. I am also adding a fan guard on top of it and then 35mm long M2.5 screws worked best for me.
Replacing all case fans
We’re also going to replace all case fans!
Bottom compartment
The bottom 100mm fans swap perfectly for 92mm Noctua Redux PWM models! You can use the included fan guards and everything! Both fans are connected directly to the motherboard using a 1x to 2x PWM splitter cable. This can be neatly routed in the compartment between the HDDs and the motherboard tray.
Top compartment
The Jonsbo N3 case normally allows for 2x 80mm fans at the back of the top compartment, the minisforum BD970i’s construction makes this impossible however.
Instead we’re going to change things up and going to use another pair of 2x 92mm Noctua Redux PWM fans at the front! This has the added benefit of being bigger then the standard 80mm fan positions and also providing a bit of airflow over the extra components we’re adding such as the HDplex 250w GAN PSU, buck-converter for 5v and the PCIe x16 BiFurcation card!
FAN decoupling
A lot of noise from high quality fans isn’t so much the fan itself making noise (the motor) but from it being coupled to something else that acts like an amplifier basically, such as a metal case!
To try and prevent this premium fans often have rubber pads at the places where the fan touches the case. The Noctua 92mm fan is an example of this!
However the price difference between the Noctua 92mm fan and the Noctua 92mm Redux edition is quite considerable. It basically just provides the fan without a lot of the extra items you get with it, which we’re not going to use anyway.
So we’re going to use 3 “home-made” solutions to try and decouple fan noise as much as possible!
- rubber gaskets
- Aliexpress has rubber gaskets for sale basically proving the same function as more premium fans have built-in, decoupling the fan housing from the metal case using a rubber pad
- o-rings for the screws
- If you want to go above and beyond you can also use some o-rings on the screw to try and decouple the fan screws from the case! How much benefit this really has is hard to say
- hard and softer plastic spacers
- To mount the top compartment fans you are going to need something to make the holes of the case fit the fan screws. You can use metal washes for this but I’ve opted to use a combination of soft and hard plastic spacers trying again to decouple the fans from the case wall