Fans in subzero environment

[Cluster]

I've been trying to find some information for a project of mine on the effects of subzero(-30 to -50c) have on your regular case fans. What im building is a duct for cold air, and from the bit of looking around i did on fan specs, some of them list -10c as their lowest operating temperature. Given the ambient outside temperatures this time of year for me, -10c is likely to be some of the warmest temperatures i'll see, and had my fair share of -50c and below last year.

Just guessing here, but i would think that the type of bearing is what would limit the operating temperature. What about the maglev style fans like those from Sunon?

[Cluster]

So basically the colder it gets the slower the fan will turn? What about pushing more volts to them to compensate? I do plan on having a voltage control on the fans as eventually this will get vented into the room its in. Perhaps i'll add in a return duct if this ends up chilling the room to much.

[EniGmA1987]

Here is a question though, if the fans are constantly running, even at -30c, would the heat produces by them spinning be enough to allow them to work for a while? Lets say 1 month? And this is continually running, no downtime at all so they wont be starting up at a super cold temperature.

And another question: as mentioned in the above post, what if the fans were overvolted to something like 15v? would the extra electricity add enough heat to let them work better not just speed wise, but temp wise as well?


On another note, if your ambient temp is -30c to -50c, why have fans run at all? Wont the air alone keep the computer cold enough?

[Cluster]

The actual ambient temp of the room its in wont be -30, im ducting in outside air that is at those temps. The ducting is feeding into a custom insulated box im building and will also feed a water cooling rad. But the run from outside to the box will be 6-7' so ya, gonna need some airflow. Hoping to keep 100cfm moving through the duct with a filter.

[tiro_uspsss]

its not the bearing can be the lube going to tar @ -50

but the motor EMF is slowed by the cold on the electrons flowing in windings

:confused: please dont tell me u mean that the electrons will slow down due to cold?

[filthysanchez]

:confused: please dont tell me u mean that the electrons will slow down due to cold?


That's what happens when things get cold...


Ever heard of absolute zero?

[tiro_uspsss]

That's what happens when things get cold...


Ever heard of absolute zero?

:rofl::rofl::rofl: puh-leeez. basic elec knowledge: lower the temp, lower the resistance = more flow :yepp: :fact:

[Vatos_locos]

filthysanchez absolute zero is a different situation :)

as metal gets colder, electricity will flow through it more easily. For most metals, this is only true up to a point. Once they reach a certain temperature, there will always be some resistance to the flow of electrical current. But there are a few interesting metals -- superconductors -- where the resistance sharply drops to zero at some critical temperature. With the resistance gone, no voltage is required to keep the current moving -- and that means superconductors can deliver electricity far more efficiently than your average wire.


at absolute zero everything stops moving so nothing can work and it's an unreachable temperature

[Cluster]

I found 4 of these Sunon's for $20, gonna give them a shot.

KD1212PTB1-6A (http://www.newegg.com/Product/Product.aspx?Item=N82E16811999029)

I wont know until mid-January how they fair out in the deep cold, but i'll be sure to post back with results :)

[Vatos_locos]

put them in the freezer :p:

[theorie]

i love when people try to talk about scientific concepts/information without having any idea what they're talking about.

like those idiots who thought an airplane on a treadmill would never take off. (remember that one?)

[zanzabar]

That's what happens when things get cold...


Ever heard of absolute zero?

near absolute zero matter changes states to a "bose einstein condensate" that has no resistance to changes in energy since it converts from a solid to a wave sign, making it essentially an energy field or waves of matter.

[cabbspapp]

i love when people try to talk about scientific concepts/information without having any idea what they're talking about.

like those idiots who thought an airplane on a treadmill would never take off. (remember that one?)

Yeah, I didn't think it could have been more obvious.