Ordered two of these to replace worn out motors in my attic. They are what they are but from my experience, expect to replace these about every 5 to 8 years if you live in the South. I've replaced mine twice within 15 years. Not knocking this motor, but the fact is, attic fans are typically useless. If I ever build another house, I won't have them installed. Gable vents and even roof top vents are usually efficient enough to allow hot air to escape the attic. And you save money in the long run. Besides, studies show that attic fans can draw cool air from your house into the attic. That's not a good thing.