Alec,
     The air in the roof space in a Florida home must get pretty significant. 
My concrete block house does not have a discernible roof vent area - just the 
holes in the overhang.  If the air could be evacuated more easily I'm sure it 
would make a difference in temperature.  Essnetually, the hot air in the roof 
should leave by natural convection - the outside air is cooler than the roof 
air and should therfore natural convect out with outside air then replacing 
it.
                                Cathy
--- Maximus 3.01
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