BRUSHLESS DC-Motor: Is the product your considering have a brushless or brushed motor?
95% of all solar ventilation (attic fan) products are sold with old styled motors which use brushes within the motors. Bottomline, you should know this because it does not matter. The warranty offered, they will wear out depending on the quality from 2 to 8yrs. So if a competitor offers you 20yr, 25yrs or lifetime the motor will fail before it reaches these years. Sure, some will send you a new