Eric Tonks wrote:
Fan motors, like other types of motors and light bulbs are stressed
the most on starting up. Run the motor 24/7/360, and it will last a
long time. I run mine continuously and it is now 18 years old.

I've been here 13 years and just last month replaced a fan motor that had
been running 24/7.

Of course the motor was the original from the '60's, so the life expectancy
of a 24/7 motor is somewhere between 13 and 40 years.