Question Powering 12V Noctua fans via USB

kristiqn1104

Honorable
Apr 8, 2014
9
0
10,510
0
Hey guys,

My laptop has :
x2 USB 3.1 Gen 1 Type A ports
x1 USB 3.1 Gen 2 Type C port / Thunderbolt 3 combined.

x3 Noctua fans :
Max. input power (each)
1,56 W
Max. input current (each)
0,13 A
Operating voltage
12 V
https://noctua.at/en/nf-a12x15-pwm/specification

Wall power outlet is not an option since those fans are attached to a cooling pad and I travel a lot ,therefore I need to supply them via USB port to stay mobile.
From what I learned so far I will need USB boost converter , to step up from 5V to 12V . This is where I get lost since I found that there will be current reduction due to voltage stepping and the converter efficiency which is about ~88%. There is also difference in USB power output depending on the generation and whether it is powering up a device or it is charging it via Superspeed standard.

Looking over USB Specifications I found the following :

USB 1.0 , 2.0 are capable of delivering up to 0.5A
USB 3.0 it moves up 0.9A with charging capability up to 1.5A
USB 3.1 claims to deliver 1.5A and 3A over the 5V bus. ( whether those values are implied when powering up or charging a device, it was not specified.)

Now if I need to deliver 0.4A to run my fans would that be possible with any of those USB ports and If so how exactly?

My intentions are to be able to run those fans via the USB port if possible at full speed.

I also own 3.0 USB non powered hub to which I want to plug those fans if it has enough juice to supply them.
https://www.trendnet.com/products/usb-hub/4-port-usb-3.0-mini-hub-TU3-H4E

I will be very grateful if you can help me out. I am not sure if this was the proper section for such kind of questions, and excuse me for my poor English!

Best Regards.
 

kristiqn1104

Honorable
Apr 8, 2014
9
0
10,510
0
With all things said and done, you forgot to mention the make and model of your laptop. If you're trying to deal with a heat issue with a concurrent laptop, you're better off with undervolting in Intel's XTU app.
I already did that from ThrottleStop app but it was not sufficient, my laptop is XPS 9570 well known for thermal throttling, what I did is I redirected the heat from VRMs to the backplate with thermal pads basically turning it into a heatsink so long story short I need efficient cooling. I bought Cooler Master Notepal U3 plus, and I am looking into replacing the fans with those 12v Noctua's.

https://www.dell.com/en-us/shop/dell-laptops/xps-15-laptop/spd/xps-15-9570-laptop

https://www.coolermaster.com/catalog/coolers/notebook-cooler/notepal-u3-plus/
 

kristiqn1104

Honorable
Apr 8, 2014
9
0
10,510
0
My VRMs were hitting 110 degrees Celsius, now they are about 85 degrees under heavy load. The back plate does get really hot and I hope that x3 55 CFM fans can deal with the issue or at least lower the temperatures with several degrees.
 
Assuming you can get those power converters to boost 5 VDC from the USB ports to 12 VDC, what you need to pay attention to is the WATTS of power each fan consumes. Watts = Volts x amps. For example, the Noctua fans' specs say 12 VDC at 0.13 W, which comes to 1.56 W per fan. Now, allowing for only 88% efficiciency in the power conversion process, that means the input to the converter must be at least 1.56 / 0.88 = 1.77 W. Round up to 1.8 W. To supply that from 5 VDC, you would need 1.8 / 5 = 0.36 A current from the USB port. That's for EACH fan. So conceivably you could connect TWO such fans, using one or two converters, so a single USB3 port. (You have not told us the power limitatioon of the converter, so we can't advise whether one of them can power more than one such fan.) But you could NOT connect three such fans to a standard USB3 port. NOTE that, although SOME USB3.1 ports claim they can deliver more than the 0.9 A max standard current limit, that is ONLY for ports designed for higher non-standard power output to be used for charging some devices. So, unless YOUR laptop says it CAN supply more than 0.9 A from each of its USB3.1 ports, do NOT assume it can.

You should realize, also, that if you do this it increases the load on your laptop's power supply by a bit (about 1.8 W per added fan), so that is a small increase in the heat generated inside the laptop to be removed.
 
Assuming you can get those power converters to boost 5 VDC from the USB ports to 12 VDC, what you need to pay attention to is the WATTS of power each fan consumes. Watts = Volts x amps. For example, the Noctua fans' specs say 12 VDC at 0.13 W, which comes to 1.56 W per fan. Now, allowing for only 88% efficiency in the power conversion process, that means the input to the converter must be at least 1.56 / 0.88 = 1.77 W. Round up to 1.8 W. To supply that from 5 VDC, you would need 1.8 / 5 = 0.36 A current from the USB port. That's for EACH fan. So conceiveably you could connect TWO such fans, using one or two converters, to a single USB3 port. (You have not told us the power limitation of the converter, so we can't advise whether one of them can power more than one such fan.) But you could NOT connect three such fans to a standard USB3 port. NOTE that, although SOME USB3.1 ports claim they can deliver more than the 0.9 A max standard current limit, that is ONLY for ports designed for higher non-standard power output to be used for charging some devices. So, unless YOUR laptop says it CAN supply more than 0.9 A from each of its USB3.1 ports, do NOT assume it can.

You should realize, also, that if you do this it increases the load on your laptop's power supply by a bit (about 1.8 W per added fan), so that is a small increase in the heat generated inside the laptop to be removed.
 
Reactions: kristiqn1104

kristiqn1104

Honorable
Apr 8, 2014
9
0
10,510
0
Assuming you can get those power converters to boost 5 VDC from the USB ports to 12 VDC, what you need to pay attention to is the WATTS of power each fan consumes. Watts = Volts x amps. For example, the Noctua fans' specs say 12 VDC at 0.13 W, which comes to 1.56 W per fan. Now, allowing for only 88% efficiency in the power conversion process, that means the input to the converter must be at least 1.56 / 0.88 = 1.77 W. Round up to 1.8 W. To supply that from 5 VDC, you would need 1.8 / 5 = 0.36 A current from the USB port. That's for EACH fan. So conceiveably you could connect TWO such fans, using one or two converters, to a single USB3 port. (You have not told us the power limitation of the converter, so we can't advise whether one of them can power more than one such fan.) But you could NOT connect three such fans to a standard USB3 port. NOTE that, although SOME USB3.1 ports claim they can deliver more than the 0.9 A max standard current limit, that is ONLY for ports designed for higher non-standard power output to be used for charging some devices. So, unless YOUR laptop says it CAN supply more than 0.9 A from each of its USB3.1 ports, do NOT assume it can.

You should realize, also, that if you do this it increases the load on your laptop's power supply by a bit (about 1.8 W per added fan), so that is a small increase in the heat generated inside the laptop to be removed.
Thanks for detailed explanation. However I think there could an easier solution.
The USB 3.1 Gen 2 Type C port specifications claim that it should supply 5V to 20V up to 5A. I addressed this to Dell to see whether they have placed any limitations to the port, otherwise I suppose I should be able to power up 12V fans without voltage converters. I found this USB to S-ATA cable which I can plug directly into one of the cables that comes with the fan accessories. I hope that makes sense!

https://www.digitec.ch/en/s1/product/startech-usb-c-to-sata-adapter-hard-drive-accessories-9720856

https://noctua.at/en/na-sac5
 
Thanks for detailed explanation. However I think there could an easier solution.
The USB 3.1 Gen 2 Type C port specifications claim that it should supply 5V to 20V up to 5A. I addressed this to Dell to see whether they have placed any limitations to the port, otherwise I suppose I should be able to power up 12V fans without voltage converters. I found this USB to S-ATA cable which I can plug directly into one of the cables that comes with the fan accessories. I hope that makes sense!

https://www.digitec.ch/en/s1/product/startech-usb-c-to-sata-adapter-hard-drive-accessories-9720856

https://noctua.at/en/na-sac5
No, doesn't make any more sense, 2.5" drives still use only 5v. 5v is 5v no mater if connected to a battery, USB or nuclear power plant.
 

kristiqn1104

Honorable
Apr 8, 2014
9
0
10,510
0
No, doesn't make any more sense, 2.5" drives still use only 5v. 5v is 5v no mater if connected to a battery, USB or nuclear power plant.
I did not understand what you mean by that. I am talking about 12V cables/devices.
Just get a 5v Noctua. They are available in all sizes from 40mm to 200mm. Just select the 5v filter from this search page:

https://noctua.at/en/products/fan
My local supplier does not stock any 5V fans and Amazon resellers don't ship to my country due to Swiss value-added tax law.
 
That USB-to-SATA cable is NOT what you think, and it will not work for what you want. It is designed to provide power at 5 VDC ONLY to a 2.5" SATA HDD unit that is designed to function properly on 5 VDC and no more than 0.9 A. That power is supplied on the two exact lines that a standard SATA HDD requires. I severely doubt any fan accessory you have will make a correct connection to those, and you STILL do NOT get 12 VDC from it!

Wait until Dell answers you. I fully expect their laptop USB3.1 Type C port does NOT do those non-standard high voltage and current outputs.

I can understand that getting some Noctua 5 VDC fans may be difficult for you. As a better and simpler alternative, instead of trying to make your own system, look for devices sold as LAPTOP COOLERS. These are flat boxes containing one or two fans designed to run from a 5 VDC power supply from a USB2 port. BUT, since they are designed for max 0.5 A current draw from USB2, their fans are not as powerful as 12 VDC 120mm Noctuas, and they would not cool as well as the design you've been trying to create.
 

Zizo007

Respectable
Feb 23, 2019
1,568
201
2,290
54
Did you try replacing thermal paste with Grizzly Kryonaut on the GPU and CPU?
You can also undervolt your CPU.
As long as your temps are under 100C you'r fine. Laptops are designed to run up to 100C. My 4820HQ always runs around 90C during gaming.
 

ASK THE COMMUNITY

TRENDING THREADS