I have lived in my home in New Mexico for 12 years (built in 1960). My bathroom had a window which was almost always open and kept any humidity problems in check. A new room was added which blocked the window....and the bathroom has never had an exhaust fan. The problem is that I don't know what type of exhaust fan to buy because my home has no attic space...nothing. It is just drywall - insulation and 2 X 8's - decking - shingles. (All lights, etc. are wall-mounted.) It seems to me that everything I look at online needs much more room to be installed. I need help!