How many watts do fans actually use?

[AustinTheIntern]

As in, let's say, NF-F12s at max speed.

[Glenwing]

1-2W

[XiaoPigs]

Noctua does have specs on their website :)

 

http://www.noctua.at/main.php?show=productview&products_id=42&lng=en&set=1

 

0.6 watts but I would say 1 maybe 1.5W

[Guest]

0.6w - P=IV

P=0.05 x 12

P=0.6

 

I= current, normally listed on the website

P= power in watts

V= voltage DC

[AustinTheIntern]

Noctua does have specs on their website :)

 

http://www.noctua.at/main.php?show=productview&products_id=42&lng=en&set=1

 

0.6 watts but I would say 1 maybe 1.5W

So if I were to use 10 fans it would consume 15W?

[joelthezombie15]

So if I were to use 10 fans it would consume 15W?

Use 2 of these for 10 fans http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=60_392&products_id=32846

[XiaoPigs]

So if I were to use 10 fans it would consume 15W?

If Noctua is right with their calculations with the 0.6w it should 6w for 10 fans but it would be safer to say 10w

[Morfy]

Some simple math listed above will do, they are negligible anyway.

[tabuburn]

You also have to take into account the starting wattage needed to start spinning the fans. Those are usually higher than the operating wattage.

 

Not sure if what Noctua means as max voltage. It could be either the max operating or the starting wattage.

 

I'll use Scythe Gentle Typhoons AP-15 as an example:

Starting current is 0.36A. If using 12V, it's at 4.32W for starting wattage.

Operating current is 0.083A. If using 12V, it's at 0.996W for operating wattage.

 

You could keep 10 of them running at 10W but you would need 43.2W to start all 10 of them. Otherwise, some won't start.

[EST_FatBoy]

You could keep 10 of them running at 10W but you would need 43.2W to start all 10 of them. Otherwise, some won't start.

Wouldnt they just start later when the first ones dont need the starting power?

[tabuburn]

Wouldnt they just start later when the first ones dont need the starting power?

That would depend how much wattage is able to be provided.

 

If you go beyond what the PSU's cable/rail/etc can provide, it'll turn itself off to prevent killing itself (kind of like a circuit breaker), depending if it has an over current protection feature built into it.

A single 12V 4-pin Molex cable/connector can typically provide up to around 132W assuming it is the only one being used in the cable (typically 3-4 Molex per cable). So you could technically run 30 1W fans off of it.

 

Fan controllers, on the other hand, don't have an over current protection, if I recall correctly. So you run risk of melting wires or frying something if you go beyond what it can provide. Although, a PSU's over current protection should still kick in.

[Glenwing]

Wouldnt they just start later when the first ones dont need the starting power?

No, unfortunately the average fan isn't intelligent enough to do staggered spinup :(