I am looking for some feedback on (1)the use of rotating vents versus standard flat low lying vents (2)the placement of these if used together — things to avoid, (3)best locations for placement on roof of a normal roof on a bungalow
The most effective attic ventilation happens with continuous soffit and ridge vents. Air will enter the attic at the ridge, run up under the roof sheathing where it carts heat away in summer and moisture away in winter, and exit at the ridge. This 24/7 attic ventilation solution is far more effective than any other type of mechanical or passive ventilation solution.
I was looking at ventilation in addition to that from soffit and ridge vents which may for some reason not appear adequate
Make sure that both the ridge and soffit vents are wide open and not blocked. For soffits, perforated soffit material is best. Just make sure no insulation is blocking the air flow from the insiode. For ridge vents, look at those sold by Air Vent, Inc. See: http://www.airvent.com/. They have a baffle design that speeds up depressurization.
Important: once this system is installed, block all other vents including gable vents as that will prevent turbulence that interferes with the air flow pattern you will have created.