Product review (5 stars): Zephyr AK2100BS
I replaced my old Typhoon, which worked for more than 12 years with no major issue except the grease on the fan cover, with this new one.  We thought it's the same model as the old one so installation should be easy and decided to do it ourselves. Oh boy, the opening of the screw holes are just off a tiny bit so it took us more than 5 hours to put it up.  But once it was finally installed, everything run perfectly. I am so happy with the different fan speeds and delay feature.