We just bought our first house and the home inspector told us we needed better attic ventilation. The house is 20 years old. Currently there are fans (electric) on the gable ends. I have yet to see/hear them go on, by the way (my instinct, from the condition of the rest of the house is that they are not working). I believe this is the only ventilation systems installed. I am planning on having a new roof installed in the near future. I need some advice on what I should be looking for in ventilation. Ridge vents, soffit vents? Should I just go with what the roofing companies suggest? What about power roof fans? I see lots of people have them. I remember installing one with my father years and years ago. But I've read a lot on the internet that they are not worth it (i.e. expensive to run for what they do)? Any info appreciated.