I can only relate the following: Once upon a time, there was a company called NuTone that made a lot of stuff, including various fans. They were all warranted for life. They were also well made. The only failures I ever had were with the QT-110 bathroom fan (but not with the QT-80). There was a problem with loosening fit between the motor shaft and the squirrel cage. NuTone replaced QT-110 fan assemblies for me every 8 years or so. Eventually, Broan brought NuTone, and honored their policy for the next 10 years. (For extra credit, find any other company that has done that.) My last replacement cost me, but the interface design seems to have been revised so it may not fail for a long time.

My NuTone kitchen upblast roof fan I use for auxiliary venting has lasted since the 70's. Of three attic ventilation fans, only one has needed a motor replacement over 20 - 30 years, depending on the attic. My 1500 cfm rated Wolf hood blower is actually made by Broan. No failure since my kitchen reno was more or less completed in 2011.

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