How to power case fans outside of a PC? Need fan recommendations for inside server cabinet!

Forums › Desktop computing › How to power case fans outside of a PC? Need fan recommendations for inside server cabinet!

neon

164 posts

Master Geek
+1 received by user: 19

ID Verified

#324936 15-Jun-2026 17:46

So.... I managed to get my self a secondhand unexpectedly/unnecessarily massive server cabinet (Dynamix), something like this: https://www.pbtech.co.nz/product/CHADNX3771/Dynamix-RSR37-6X6-37RU-Server-Cabinet-600mm-Deep-6

When i plugged everything in, the fans were stupidly loud (maybe by design, maybe they were just old). So, i figured i could probably chuck few case fans into the module and see if i can make it a bit quieter (ideally noctua but i will settle for something cheaper to begin with).

The existing fan module looks something like this: https://dynamix.co.nz/RAFANKITT
It seems like 4x 120mm fans. All fans seem to be AC powered (you can sort of see from the 2nd photo), theres no real power supply, just direct AC cable split into each fan by the looks of it.

aaanyway, this is for homelab purposes. and i only plan to put some of my network gear, nas, and couple of mini pcs in here, so its not going to drive much heat (i probably dont even need any fans tbh). Fan would be nice to make some air pressure inside to keep insecs away maybe? ...and to keep some of the dust away. i want to try put some case fans in its place, like this: https://www.amazon.com.au/gp/product/B07HC7P3HJ/?th=1

Im open to alternative suggestions (need 4 fans, ideally cheap-ish).

So, im hoping to just be able to unscrew and remove all the AC powered fans, and try to screw in these case fans. But, where im stuck is that im not sure how i can power/control them? Are there some USB/DC powered fan controller i can buy to plug these into?

If anyone has any alternative (not too expensive) solution, please let me know? Id rather not buy AC powered fans though.

1 | 2

2732 posts

Uber Geek
+1 received by user: 1190

#3503337 15-Jun-2026 17:52

12v case fans are common as mud. add in 12v dc output power supply your good to go. i've reused old laptop power supplies, but there is a wide range of hobby to pro level power supplies. plus there is also 12v fan controllers you use.

neon

164 posts

Master Geek
+1 received by user: 19

ID Verified

#3503342 15-Jun-2026 18:21

tweake:

12v case fans are common as mud. add in 12v dc output power supply your good to go. i've reused old laptop power supplies, but there is a wide range of hobby to pro level power supplies. plus there is also 12v fan controllers you use.

Sweet, yeah i have a bunch of 12V power supplies saved up - otherwise i can use a type c charger which is likely better if that is an option. I can very easily order those amazon fans i linked (or something else if anyone recommend anything better value). Could you or someone please help me find this fan controller i can use?

Ive looked at aliexpress and there seems to be lot of hits. but lot of them are SATA or 4 pin PC powersupply port powered (can/should i get a converter for this?). Is there a difference between PWM vs no PWM? Some of the PWM fans on the same brand are only a little bit more expensive, would be nice to have the ability to dial it down. can a Non PWM fan be plugged into a PWM fan controller? Can a PWM fan be plugged into non PWM fan controller?

richms

29311 posts

Uber Geek
+1 received by user: 10396

Trusted

Lifetime subscriber

#3503356 15-Jun-2026 19:53

PWM 4 pin control is usually the preferred way with fans now to slow them, dropping the voltage will still work but you have issues starting and as the fans age they will slow down and possibly stop till you up the voltage a little.

The problem is you will find PWM speed controllers which are chopping up the supply power. with 4 pin fans its a separate input, you need to give fully on 12v to the fan too. If you PWM the power to the fan its about the same as dropping the voltage to it for problems.

I suspect that they just use the same guts for the fan and put a 3 or 4 wire cable on depending what they are selling them as. ESP32 can generate a PWM signal and let you control it from home assistant or whatever.

Richard rich.ms

Tinkerisk

4963 posts

Uber Geek
+1 received by user: 3910

#3503368 15-Jun-2026 20:45

I use four Noctua industrial PWM fans (inexpensive and only slightly louder than standard Noctua PC fans) with a temperature-sensor controlled pcb (aliexpress) and a 12V/1A wall-plug power supply for a 12U network cabinet that houses several mini-servers.

It’s deliberately kept simple to ensure the fans never stop running under any circumstances—even during a power outage or if Home Assistant fails—which is why the power supply is plugged straight into the „last box standing“ of two available UPS outside the cabinet. Both UPS units are connected via USB to a NUT server (a good old low power 32-bit Raspberry Pi B, who is still doing a great job). 🙂

Detractors claim that traces of a power management system logic from a large airliner can be found in my network's cooling and power management setup—but that’s not true—honestly! Really, it isn't! It is far too small and inconspicuous for that. „Manual override“ is not a worldview; it is essential for survival. 😉

Qui nihil scit, omnia credere debet. - He who knows nothing must believe everything.
Firewalls do NOT stop dragons. Really not!
I avoid Big Tech. They try hard to dictate technology and „culture“ across borders.
In effect we have everything to hide from someone, and no idea who „someone“ is.

fe31nz

1310 posts

Uber Geek
+1 received by user: 438

#3503422 15-Jun-2026 23:29

If you have a spare Molex connector on a PC's power supply you can pull it out the back of the PC via an empty slot and connect to that. There are lots of options for extending PC Molex connectors and splitting the cables and converting Molex to fan connectors. But at 12 volts you do have to watch for voltage drop over long extension cable.

fearandloathing

548 posts

Ultimate Geek
+1 received by user: 212

ID Verified

Lifetime subscriber

#3503430 16-Jun-2026 07:42

I did the same with a smaller cabinet

I used a Meanwell power supply, this one I think

https://www.jaycar.co.nz/25w-12v-2-1a-enclosed-power-supply/p/MP3297

with some noctua 12v fans

Mighty Ape

Shop now at Mighty Ape (affiliate link).

Yoban

462 posts

Ultimate Geek
+1 received by user: 92

#3503443 16-Jun-2026 08:56

Hi there - was and still in the same boat as you from a few years back with a 42U unit....

Interesting to note "The existing fan module looks something like this: https://dynamix.co.nz/RAFANKITT" you mentioned has a thermostat attached to it...

I looked at using a fan controller Like this one which would sit within a box and take my power cable for the fans, cut it and feed it in to and out of the control box.

This maybe a simple solution

neon

164 posts

Master Geek
+1 received by user: 19

ID Verified

#3503514 16-Jun-2026 12:43

Thanks for all the input/suggestions.

Is there any reason to get a more expensive fan controller? Can i potentially get something cheap like this: https://www.aliexpress.com/item/1005011940267107.html

...and then add an 4 pin 1 -> 4 (or 5) splitter like this: https://www.aliexpress.com/item/1005007263489002.html

Then just plug in any 12V DC Power supply (with more than 12w) or type c. And buy some PWM fans x4.

Anyone see any problems with this?

...Does anyone recommend any cheap PWM fans (i guess high airflow, low cost, low noise)? Im hoping to spend around $10-20/fan at most - cheaper the better.

fearandloathing:

I did the same with a smaller cabinet

I used a Meanwell power supply, this one I think

https://www.jaycar.co.nz/25w-12v-2-1a-enclosed-power-supply/p/MP3297

with some noctua 12v fans

Oh that looks quite nice. You just ripped apart a fan header and connected the wires directly to the PSU? Noctua fans are supposed to be fairly slow if i recall, do you get a decent amount of air circulation in your unit?

Im hoping the 120mm fan holes line up with the enclosure haha, otherwise i will need to do some janky cable tie or drill holes - i would rather not.

MaxineN

Max
2138 posts

Uber Geek
+1 received by user: 1759

ID Verified

Trusted

Subscriber

#3503527 16-Jun-2026 13:31

This is what I did with my Dynamic 27U as I was in the same boat as you.

I removed the AC fans entirely.

https://www.aliexpress.com/item/1005009048808356.html Bought one of these. You power it with a bog standard Huawei 12V 2A plug that came with your router.

https://computerlounge.co.nz/products/arctic-p12-pro-pst-co-120mm-black Bought 4 of these.

PST = PWM with Sharing Technology, so you can daisy chain all of the fans and use one header out of the 6. This leaves you with room to grow providing you upgrade your power supply or manage your fan speed, which is really easy.

There are probably much better setups, but this is mine and I love it.

Ramblings from a mysterious lady who's into tech. Warning I may often create zingers.

Want broadband cheap and made for tech enthusiasts? Go look over at Quic. Use R177510EBNVXP for free setup at check out.

fearandloathing

548 posts

Ultimate Geek
+1 received by user: 212

ID Verified

Lifetime subscriber

#3503536 16-Jun-2026 14:16

You just ripped apart a fan header and connected the wires directly to the PSU?
yes

do you get a decent amount of air circulation in your unit?

Probably, judging by holding my had on the services that get warm

Im hoping the 120mm fan holes line up with the enclosure
in my case they did

MikeAqua

8314 posts

Uber Geek
+1 received by user: 4043

#3503543 16-Jun-2026 14:53

I have one of these OpenFan controllers on the way. All going according to plan (unlikely) ... it can be used to control multiple fans independently. Responds to API commands and has a bunch of configurability. I plan to control it via a Pi Zero.

I have no idea if they are any good. Looked like a great idea, so I thought I'd support.

Mike

Geekzone support

Support Geekzone with one-off or recurring donations Donate via PressPatron.

richms

29311 posts

Uber Geek
+1 received by user: 10396

Trusted

Lifetime subscriber

#3503547 16-Jun-2026 15:04

Other than the machine I kitted out with noctuas to keep it quiet in a media centre case, I have just ordered cheap fans off aliexpress. I think the 120s I got to fill every hole in a tower case were about $8 each inc shipping a while ago, so with the junk dollar at the moment probably $10ish or so.

Also got some of these things which help a bit with the noise when combined with using the rubber snap in fan holders instead of screws.

https://www.aliexpress.com/item/1005007745028648.html

https://www.aliexpress.com/item/4001062788478.html

After looking at a few 120mm fans on there, they start to appear in the combo deals at better prices so no point linking to a specific one, as the listings I bought from all have a normal price about $24 so they can show stupid discounts in the bundle deals.

Richard rich.ms

neon

164 posts

Master Geek
+1 received by user: 19

ID Verified

#3503549 16-Jun-2026 15:09

MikeAqua:

I have one of these OpenFan controllers on the way. All going according to plan (unlikely) ... it can be used to control multiple fans independently. Responds to API commands and has a bunch of configurability.

I have no idea if they are any good. Looked like a great idea, so I thought I'd support.

Oof thats pretty expensive - looks cool though.

I did see a bunch of esphome projects for pwm fan controllers, so maybe at a later date i can build one and connect it upto home assistant. But then i thought, what would i need smart functionality for the fan though - i think my devices would function easily without any fans at all. Main reason for the fans in my case is to create some positive pressure/airflow so it may slightly deter insects - so i can very easily set it to a good enough speed and let it sit there (i almost have no use for PWM fans either TBH). I suppose i can always plug a $10-20 smart power plug on the PSU and flick it off/on remotely if i need some smart functionality too. I dunno, im just cheap HAHA

neon

164 posts

Master Geek
+1 received by user: 19

ID Verified

#3503552 16-Jun-2026 15:18

MaxineN:

This is what I did with my Dynamic 27U as I was in the same boat as you.

I removed the AC fans entirely.

https://www.aliexpress.com/item/1005009048808356.html Bought one of these. You power it with a bog standard Huawei 12V 2A plug that came with your router.

https://computerlounge.co.nz/products/arctic-p12-pro-pst-co-120mm-black Bought 4 of these.

PST = PWM with Sharing Technology, so you can daisy chain all of the fans and use one header out of the 6. This leaves you with room to grow providing you upgrade your power supply or manage your fan speed, which is really easy.

There are probably much better setups, but this is mine and I love it.

I think thats a better controller than what i was looking at, i may get this instead!

I already had this in my cart (https://www.amazon.com.au/gp/product/B0DJDDCG4M/), which is the 5 pack of what you recommended, so glad im not completely off. I was debating because this one was almost 2x the other arctic ones (https://www.amazon.com.au/gp/product/B0DPQZLN3V/ and https://www.amazon.com.au/gp/product/B07HC7P3HJ/ [not PWM]), but this one has 2x more RPM.

richms:

Other than the machine I kitted out with noctuas to keep it quiet in a media centre case, I have just ordered cheap fans off aliexpress. I think the 120s I got to fill every hole in a tower case were about $8 each inc shipping a while ago, so with the junk dollar at the moment probably $10ish or so.

Also got some of these things which help a bit with the noise when combined with using the rubber snap in fan holders instead of screws.

https://www.aliexpress.com/item/1005007745028648.html

https://www.aliexpress.com/item/4001062788478.html

After looking at a few 120mm fans on there, they start to appear in the combo deals at better prices so no point linking to a specific one, as the listings I bought from all have a normal price about $24 so they can show stupid discounts in the bundle deals.

Oh thats useful, thanks for these, i will order some of these as well!

MikeAqua

8314 posts

Uber Geek
+1 received by user: 4043

#3503561 16-Jun-2026 15:30

neon:

Oof thats pretty expensive - looks cool though.

I did see a bunch of esphome projects for pwm fan controllers, so maybe at a later date i can build one and connect it upto home assistant. But then i thought, what would i need smart functionality for the fan though - i think my devices would function easily without any fans at all. Main reason for the fans in my case is to create some positive pressure/airflow so it may slightly deter insects - so i can very easily set it to a good enough speed and let it sit there (i almost have no use for PWM fans either TBH). I suppose i can always plug a $10-20 smart power plug on the PSU and flick it off/on remotely if i need some smart functionality too. I dunno, im just cheap HAHA

Depends how you look at it. For me it's hours of entertainment, just to achieve half of what I originally planned. 😆 Half of the things I do/buy are just for the curiosity factor/challenge.

If you don't need variable speed, then yeah ... you just need power, not dynamic control.

Mike

1 | 2