I’m looking to my RPI4 with SATA HAT Quad…
1 fan on CPU under HDD
1 fan on top of HAT.
All extract air outside.
But I’m in doubt regarding CPU FAN entry airflow. Not sure holes under SATA HAT kit provide enough entry point.
May be usefull to add hole on lateral of body ? Or add a fan in push to under plate (with appropriate support ) ?
Any feedback from engineers team about theses questions ?
Reversing Fans, may be good idea. I’ve already replace top fan by Noctua for better flow.
Also changing thermal paste of CPU for paste provided by Noctua.
I’m keeping your proposal for later in case of I need to open my HAT SATA Box 
I’m begin to work on add 2 fans XM-2 NB BlackSilentFan (unfortunately require 12V power need to find on) on bottom of case with dedicated support push airflow to bottom case radiator + holes for the motherboard.
Hello StephaneP. Can you say which Noctua fan you are using? Does it adjust speed? I’m having some difficulty finding a 3-pin 40mm x 10mm 5v PWM Noctua. Could be I just haven’t hit on the right combination of search terms!
Noctua NF-A4x10 (3 wires)
You need to cut plastic plug very short.
Thanks for the tips! New fan on the way.
I’ve also drilled out the holes on the bottom plate to a larger size…I’m not certain that has helped…maybe some extra clearance on the bottom would help. The Pi4 starts out hot by its nature and putting it in a small case doesn’t help matters I suppose. Nice case and I like the size but for temps…not the best I guess.
I’ve tried running without external body : HDD at 32°C versus 50C° with body.
Now using the Noctua fan mentioned, 3-wire, 5v. Unfortunately it did not moderate speed with temp but ran %100 all the time. That helped cooling but was loud enough to be distracting. I then took the resistor out of a Noctua low-noise adapter I had laying around and put that in line. It does make it quieter but seems to cool, at least, a couple degrees better than the stock fan.
At a guess, and going by data on other fans in the same family, the resistor slows the fan from 4500 rpm to , probably, 3700 rpm. Quiet enough. I’ll live with the temps I have now. Temps seem to range from 46 to 47C at idle.
I have not tried removing the case…may be worth a try though not very pretty. I have tried removing the top cover and that may help a couple degrees. I wonder if lifting the case a bit, creating a gap on the bottom above the mounting plate would help. The case cut-outs prevent that…gotta wonder though.
After reading and based on some suggestion on here I also bought a noctua with 3 wires, and ofc the fan runs at full speed, which is not quiet at all, ended up adding a 50ohm rezistor on the 5v wire (red) which reduced the rpm to a quieter noise level
Looking trough the code of the rockpi-sata service they are actual using 2 PWM pins from GPIO on the PI, so in fact it seems that the fan is PWM (i assume), the confusion I believe is that the original fan is 3 wire, but those wires are not GND, Voltage regulator and 5V, but GND, PWM, 5V
Would be great if someone from the team confirm this, because if this is true, there is a pwm fan from noctua, almost identical to this one
Also the temps didn’t improved, in idle with 4hdd i got 57-58 on cpu and 52-53 on hdd, which is bad
This morning i drilled some holes next to the power plug, reversed the cpu fan to blow on the heat sink and the top fan exhaust - this ended up with 52-53 cpu and 44-46 hdd temps on idle, still not great but at least the hdd are little cooler
This needs an additional fan to add aer in, somewhere on the back, it’s plenty of room there
a small project i’m intending to embark on would be to purchase the 30mm x 30mm x 3mm blower fan below and cram it into the chasis to provide some air pressure down to the bottom PCB… just need to figure out where to wire the fans to though…
[quote=“SsilviusS, post:10, topic:3595”]
…This morning i drilled some holes next to the power plug,…[/quote]
Have you pictures where you make holes please ? I’m thinking to make some + 1 more to retrieve access to USB-C and my MicroSD too
Heatsink Fan have 1 of screw have plastic cover, any problem to unscrew it ?
Use USB2 port 
or USB-C (if you have a spare USB-C connector and make hole in box)
is there a name or brand to this, looks promising?
for power it depends if it’s 5v or 12v, but the PI and hat have plenty of options
no problem at all, but you will need a washer for the screws as in reverse they are too long, you could use the ones from the top fan, they are o bit shorter
12v but start at 9v --> XM-2 NB BlackSilentFan
i’m trying my best not to make a hole in the box… i dun have the tools to drill metal in my apartment… using the USB2 port or USBC port is quite out of the question… i’m thinking of using 3pin splitters and connect the fans all to the top-hat, since they are all 3pin…
Nice IDEA !! I will think about too but not for my expected fan (XM-2 NB BlackSilentFan) 12V. I’ve to find 5V fan or may be another Noctua NF-A4x10 may be 20mm version.
i think its best to just stick with 5V fans… is you wanna use 12V fans, you either got to take power off the GPIO pins or hack together from a usb-C connector… 5V fans makes the cleanest build…
@setq, do you know the fan connectors on the top board are what kind of sizes? are they SH1.0mm, ZH1.5mm or PicoBlade1.25mm type? i’m trying to buy the right connectors to do the surgery…
I’ll let you know when I check the specifications tomorrow.
