I bought a 50 cfm bathroom fan and the install kit. I have to drill a hole in my house for the vent! But my question is the room I am trying to vent is like 25x12 ft. Is 50 cfm overkill? And is it going to cost a lot to run 24/7? Can I wire it to a dimmer switch? Please help I am going to install tomorrow and a friend will be doing the electrical work!