Hi Guys

Yep I put some research into this and havent come up with any real intelligent way of switching my powersupply's fan, more specific the direction of air blow of my powersupply's fan.

I have a CoolMaster Real Power Pro 650W Power Supply. In the manual it says that it is a "120 mm fan with intelligent speed controller" which makes it run nearly silent but it doesnt say anything about the direction of airblow.

After reading a few guides on overall case cooling I found out that its more preferable to have the power supply fan blow out if your rear fan blows out as well to prevent creation of "short circuit" in airflow. I have front fan blowing IN...side fan blowing IN...rear fan OUT...powersupply fan UNSURE(but i suspect its IN).

So far the only thing I have been able to figure on how to reverse the airblow direction is unscrewing the powersupply...unscrewing the fan...put it in reverse position and screwing everything back together.

I am not 100% sure it can be done and dont really want to mess with unless I know that this method will work. If you guys know of any other way to do it please let me know before I destroy my power supply




Thanks All

It seems like you're asking two questions here.

1. How can you tell the direction of airflow?

--- Most power supplies will take the air inside the case and blow it out the back. Simplest way to test this is to take a small, thin piece of paper (like a piece of toilet paper...preferably clean ), and when your computer is on, take off the side panel and hold the paper up to the 120mm fan. If the paper gets "stuck" to the power supply, that means it's drawing air in from inside the case, and thus spitting it out the back. That is the preferable setup.

2. Can you "flip" the fan?

--- I don't know that particular power supply, but most likely, yes you can. When you open up the PSU (unscrew the screws holding the "cover" in place), you should have access to the fan. Two important things to note: 1. You'll void the warranty by opening it up, so only do so if you absolutely need to, and 2. Obviously the power supply should be off and unplugged from the wall, but remember that there are still capacitors inside, so don't do anything stupid .

Hope that helps.

I'm almost 100% sure that it blows out.

The fan will definitely be blowing over the components in the PSU and be channeled out of the back.

Leave it how it is unless you know exactly what you are doing.
It's set up that way because certain components in the PSU need airflow to operate within normal tolerances.

Alright guys I checked the direction of airflow of my powersupply the way ClayMeow suggested and it seems that the air is definitly blowing out. I am really happy that i dont have to mess with it at all. I guess since I have that intelligent fan speed control its hard to determine which way it blowing because its barely blowing at all. really wish i could manually turn it up which would greatly benefit my CPU temperature.


Also jammin I dont think you are right because thinking about it ... it really doesnt make sense for PSU fan to be blowing in because it would just blow hot air from PSU into the case and more directly on the PCU.



Once again thanks Guys

Jammin just worded it oddly. He meant this same thing I said...it's sucking air from inside the case and blowing it out the back. If it did it the other way around, it would technically be better for the PSU components (as the outside air is cooler), but then you'd be putting the hot air into the case, which wouldn't help your cpu and motherboard much. The way it is now, though slightly warmer air will be pulled into the PSU initially, it's more about getting airflow thru the PSU components and removing the hot air, rather than having cool air blowing on it. Heat can be combated in two ways, either blowing cool air on something, or removing hot air....PSU's do the latter.

I obviously wasn't very clear. The description I gave meant the PSU takes air from inside the case, blows it over the components inside the PSU, then it gets blown out of the back of the case.

edit - and Clay beat me to it.. worded oddly indeed.

oh im sorry jammin I had that confused.

You guys were good help.

Also if anyone has any good suggestions on how to increase the PSU fan speed please let me know