Well now that i have a few ladies in a cold room (50 degreesF) I decided to not use any ventalation because of it dropping the temps. Also I've read that opening your door, window, shed once a day for the time you work and admire the ladies is enough for them to breath.

As for the fan why go through the hassle of buying/selling and getting a weaker fan, when I'm sure you can buy a fan speed controller.