Can blocking off a fan kill it?

[VirtualLarry]

I have an Antec 300 case, with all fans installed. I had been running it with a keyboard covering the top, including covering the fan. It has been that way for several days.

I took the keyboard off of the top just now, and the top fan is not running. Is it dead? Did I kill it? I would have thought that it would keep running.

Edit: Hmm, maybe it's not dead. I took a mini-screwdriver and jump-started it.

 

[dac7nco]

Fans won't work harder if you stress them; I have a Lian-Li PC-P80 stuffed with expanders right behind a closed door, and the front-door fans have been fine. If you were in vacuum the fans might spin a little faster, but that's it.

Daimon

 

[pcgeek11]

A fan will draw less current when blocked than it does when moving air.

Less work = less power needed.

Sound weird but it is true.

 

[Tsavo]

I have an Antec 300 case, with all fans installed. I had been running it with a keyboard covering the top, including covering the fan. It has been that way for several days.

I took the keyboard off of the top just now, and the top fan is not running. Is it dead? Did I kill it? I would have thought that it would keep running.

Edit: Hmm, maybe it's not dead. I took a mini-screwdriver and jump-started it.

Mine does the same thing uncovered.

 

[yottabit]

Fans won't work harder if you stress them

Not entirely true. As someone else pointed out, they do draw more current the more the back pressure increases. This will continue to increase until the fan reaches it's static pressure (which is usually not rated for computer case fans)

I could easily see killing cheaper computer case fans by running them at their static pressure. I'm sure it at least dramatically shortens their lifespan. The increased heat and back pressure could damage the circuitry or destroy the bearings.

Is your fan hooked up straight to the PSU or through the mobo header? Could be the system throttling the fan, but if you need to "jump start" the fan to get it to work I'd suggest replacing it.

 

[Rubycon]

Most fans you see in computer chassis' are of the unloading design - where RPM (which is inversely proportionate to motor load) increase as the pressure increase. These are electronically commutated (i.e. brushless) designs. Even if you jam a fork in the fan it can remain powered on for days and not suffer damage. They have built in locked rotor protection.

Go ahead and try it for yourself! (Carefully) slow down the fan by putting pressure on the hub until it stops. Then hold the blade gently with your finger and you will feel the motor "trying" to start. It will pull, then stop and repeat this cycle forever. (or until you let it go and it starts moving again)