Danny wrote to me and asked:
Do i have to put turbines on my metal roof?
Turbines are used to vent excessive heat and moisture out of attics. There is nothing specific about a metal roof in most cases that increases the need for ventilation including turbines.
However, I am a strong believer in good attic ventilation consisting of intake vents and exhaust vents. In ideal situations you want to bathe the entire underside of the roof deck with fresh air continuously. Soffit and ridge vent combination can be an effective way to do this on many homes.
Also keep in mind for enhanced energy efficiency that one option is a metal roof with reflective pigment in the paint.