I am using a small room in my basement to store wine. I want to install a 5000 btu window air conditioner. I can either vent it into my basement or vent outside through a window that I can close up. My question is: Does the unit have to vent into the basement to avoid drainline freezing in the winter, or can I use the window. The complication is that to vent into the basement I need to open a hole in a brick wall. I am running at 70 degrees and 80% humidity currently.