CFD Model of 3 fans and 2 chambers

I need a simple CFD model of 3 fans each in their own individual chambers which pulls air from a large chamber and discharges it into a large chamber. I need to know whether if turning off one fan will cause back draft. Please see this youtube clip to understand the concept... [login to view URL] I will supply the winning bidder with the dimensions of the chambers and the fan specifications. Please read the project first and write the word "Understood". Also write your steps and suggestions to complete the project with a short description of what you understood.