I have a 65-square-foot bathroom and I'm replacing the current bathroom fan. I'm looking at getting a Panasonic model that has a switch between 80 CFM and 110 CFM. I know the rule of thumb is "1 CFM per square foot", so 80 CFM would technically be "more than enough", but is there any harm in setting it to 110 CFM (other than slightly increased energy costs and maybe a little extra noise)? It wouldn't have to run as long that way, right? And would be faster to clear out, say, the bathroom mirror after a hot shower?