Great fan, quiet on low speed and still push a TON of air.  Made this blazing summer bearable.  One note- if you have an older house without A/C you also likely have beautiful old wooden windows with original wavy glass.  If this is the case then it's likely this fan won't fit those windows because while the diameter of the fan itself is 20" or whatever, the casing around it won't squish down enough to fit.  I remedied this by swearing and then jamming it into the frame slight sideways and pulling the casing down over the top.  Not ideal but the measurements they give (minimum 26.5") is for real- no cheating.