PSU up or down?

[Apothem]

Just ordered all my parts and have been going over the build in my head,

 

http://pcpartpicker.com/part/xfx-power-supply-p1750bbefx

 

and the coolermaster haf 922 case, 

 

should i face the fine intake so i draws air from the case and exhausts out the bottom,

 

or draw from the outside and exhaust inside?

[Godlygamer23]

It won't exhaust inside. Both ways, it'll exhaust out the back. I'd point the fan towards the bottom of the case.

[acidydragon]

Generally speaking, cases have a fan filter built in on the bottom where your PSU sits, so down would give it a filter.

[Stav Kats]

If you don't have a carpet under your pc you can use it either way. However, I would recommend placing with the fan facing up so it can take fresh air from the intake fans from the front of your case. Also, it removes the hot air from your GPU making your inside of the case cooler.

[Hyydrah]

Just ordered all my parts and have been going over the build in my head,

 

http://pcpartpicker.com/part/xfx-power-supply-p1750bbefx

 

and the coolermaster haf 922 case, 

 

should i face the fine intake so i draws air from the case and exhausts out the bottom,

 

or draw from the outside and exhaust inside?

Whichever way is more aesthetically pleasing is best to me. Some PSUs require a particular orientation though, such as SeaSonic's fanless PSUs (don't worry, it explicitly reminds you to do this).

[Hyydrah]

If you don't have a carpet under your pc you can use it either way. However, I would recommend placing with the fan facing up so it can take fresh air from the intake fans from the front of your case. Also, it removes the hot air from your GPU making your inside of the case cooler.

Temperatures aren't noticeably affected based on my testing as well as other watercoolers such as Tom Logan from Overclock3D, though PSUs generally look better when the fan is facing up. This also doesn't necessitate the removal of the sticker (for aesthetic purposes) usually located on the bottom, typically saving your warranty.

[extremescouter]

If you have a fan filter underneath your case, I would say fan facing down, to draw air into the PSU. 

[nsyedhasan]

If the case is completely against the floor, so much so that it wouldn't be able to take in air, you should place it facing upwards. And if this isn't a case then upwards of downwards your choice.

[Jamdude]

I always have my PSU so the fan faces down at the bottom of the case.

[Electronics Wizardy]

Point the fan in the case unless you can be shure that their is going to be enough air going in the fan. One way to check for this is making shure the botton is elevated from bottom and that there is a whole at the bottom.

[Scia]

Fan at the top: Less dust sucked in from floor / table, but some dust from the case's interior.

 

Fan down, some dust from the floor / table [if you have a fan filter barely any], more fresh air.

 

Exhaust is at the back no matter which way.

 

I always mount mine face down. [Especially in WC set up, if it leaks, not inside the PSU ^^]

[KaareKanin]

Either way the PSU will exhaust the same place the power cable connects, and I don't think that'll be on the inside of your case. I prefer do have the fan pointing down, especially if you bottom mount it and have an air filter at what would be the PSUs intake.