Attic Ventilation: Is a Roof Fan Worth It?

My power attic ventilator fan has died after 22 years. I had a new roof put on 6 years ago and I now have ridge vents on both my hip roof and gable roof. My soffits are well vented. Is it worth replacing my roof fan on my hip roof? I am thinking it might be a good idea since the ridge vent on a hip roof is not very long. I have heard conflicting theories about this. What about a power roof or gable vent on my gabled roof? Thank you for your help.

The Money Pit Answer

Unless you are seeing any evidence that a moisture problem is developing (condensing, rusty nail tips from roof shingles, mold) I'd recommend eliminating the attic fan.  Using it would provide very limited amount of additional ventilation.  It will essentially draw air in from the ridge vent and exhaust it through the fan, creating a useless circle of intake and exhaust.  A continuous ridge and soffit ventilation system is a much more effective and efficient way to ventilate the attic.