power supply fan position and airflow

I am a bit puzzled but welcome any help I can get. I purchased a new Rosewill Power Supply. Unlike my old power supply, the new power supply's fan is not on the back of the tower supply, but on the bottom of it. The power supply is mounted on the top and rear of the case. My question, does the fan draw air from inside the center of my pc (where the fan blades are) and expell it out the rear "mesh" looking cover where the power cord and volt setting is? Thanks for the help

That precisely what it does. The botton fan draws air in there for cooling the tranformer and caps inside and expells that out the rear of the case. Some supplies see two fans while many like the one there only see one large fan but still have a rear vent.