To get a PC fan to reverse direction?

**judoGTI** · 05-17-2007, 11:28 AM

Hey everyone, Im building my own laptop cooler and have question. I want to use a blower style fan to keep the cooler to a minimum size, but I need these fans to suck in, instead of their natural ability to blow out.

If I just switch the positive and negative wires will I accomplish this without any ill effect?

Here is a pic of the fan I want to use, just a typical blower style fan with a pos and neg wire to power it.

**kevinlekiller** · 05-17-2007, 11:34 AM

It depends on the fan , some fans have some sort of an electronic circuit in it , and if you plug it in backwards it doesn't work.

**xBrady** · 05-17-2007, 12:27 PM

Flip the fan around.

**shiltz** · 05-17-2007, 12:54 PM

Even if it does spin in reverse when you switch the pos and neg it will not move much air as the blades are designed to push air in one direction only, only way to reverse it is to take the fan out and flip it if posible.

**psyrex** · 05-17-2007, 01:52 PM

Originally Posted by shiltz

Even if it does spin in reverse when you switch the pos and neg it will not move much air as the blades are designed to push air in one direction only, only way to reverse it is to take the fan out and flip it if posible.

, but you can't take it out and reverse it. With a regular box fan, you can just point it in a different direction, but not the fan you posted.

**jjh221** · 05-17-2007, 09:08 PM

Originally Posted by xBrady

Flip the fan around.

lol, i was thinking the same but he wants the side vents prob to blow not suck.

**Motoko** · 05-17-2007, 10:09 PM

buy a left hand fan?

**turbocad6** · 05-17-2007, 11:59 PM

Originally Posted by shiltz

Even if it does spin in reverse when you switch the pos and neg it will not move much air as the blades are designed to push air in one direction only, only way to reverse it is to take the fan out and flip it if posible.

that is just not true, a fan like that will reverse airflow with reverse rotation, as will most any fan, the blades are pitched at an angle that will cut & move air one way or the other..., if it was a squriel cage design then it'd be affected by housing etc, but not one like this...

**kevinlekiller** · 05-18-2007, 12:29 AM

Originally Posted by turbocad6

that is just not true, a fan like that will reverse airflow with reverse rotation, as will most any fan, the blades are pitched at an angle that will cut & move air one way or the other..., if it was a squriel cage design then it'd be affected by housing etc, but not one like this...

**Rob Withey** · 05-18-2007, 02:17 AM

Originally Posted by turbocad6

that is just not true, a fan like that will reverse airflow with reverse rotation, as will most any fan, the blades are pitched at an angle that will cut & move air one way or the other..., if it was a squriel cage design then it'd be affected by housing etc, but not one like this...

It will probably move air, but not as much. The blades are designed to work in one direction. They have a slight curvature to them that will be reversed if working in the other direction.

Don't believe me? Just got and look at the blades on a fan to see the curvature.