CORSAIR CMPSU-850HX 850W ATX12V 2.3 / EPS12V 2.91 80 PLUS SILVER Certified Modular Active PFC Power Supply
I am not sure how to mount the power supply... the case has the PS at the bottom, not top. I know which part of the PS is at the back of the case ie the part with the power plug and switch (Captain Obvious!!!) but not totally sure if the large fan needs to point up or down inside the case. if its pointing up, won't it be sucking hot air from the CPU and cooler, but if down, won't it be sucking air straight from a flat surface???? not sure if my question makes sense...
makes little or no difference. I have mine mounted fan upwards in my Antec 1200... bit pointless having the fan facing down as there is minimal room under the PSU and no bottom vent on the floor of the case
^5 +1 what ulysses35 said. In your case the psu should be mounted with the fan on top. Yes it will pull in warm air from the case and exhaust it out the back of the case. That is a typical configuration. It's okay! Don't worry! Be happy!
I have Antec 900 cases. I mount the PSU with the fan facing up. The only things generating heat in the bottom of the case are the two or three hard drives mounted in the lower drive bays.
HD temps in the case with three drives (one WD 640 Black and two 1 TB Greens) have never exceeded 29 C. and PSU exhaust air is about 3 C. over ambient. The other fans handle the CPU and GPU temperatures.
zipzoomflyhigh - I think that first part was in response to the OP's comment about the psu fan sucking in warm air from the cpu. At least that's the way I interpreted it and ulysses35 did mention that it was pointless having the fan facing down.
era86 - Mounting the psu fan side down over an opening in the bottom of the case is an option. The concept is that if there is sufficient ventilation, air flow, and cooling for all the components in the system, then the psu can be mounted fan side down so it can draw in fresh air and cool itself. One just has to be careful not place the case directly on the carpet as it could block air intake. A few years ago I built myself a custom pc stand with casters. Carpet problem solved and I can move the pc very easily.
Just to avoid confusion, the Antec 1200 does not have an opening in the bottom rear of the case while the CM 690 does.