That really depends on what you are trying to learn. Are you only interested in the air circulating through the room? In that case you could simply use a fan curve (and maybe input a swirl). If the fan design is important, then you will need to model the fan and use a rotating region.
Hi Amit thanks for your reply. I am only interested in the air circulation in the room. I am new to flow simulation. Would you give me some recommendations on books or resources that I can learn more about the subject matter?
The training manual is available from your reseller when you take the Flow Simulation course. There are other publications available for the software and I'm sure an Amazon search will provide you with more than a couple. Also, there are a number of tutorials on SOLIDWORKS' blog by Marie Planchard.
The problem as you've stated can be treated as an internal flow problem with mulitple rotating regions or, as Amit has stated, prescribing a fan curve and swirl on to simplified geometry. Your "room" will need to have inlets and outlets, which would be the venting (hot/cold and cold air return) in real life. (pressure boundary conditions would suffice)
If you have Flow premium then you can also account for radiation such as what would be found through and around windows.