I'm turning to the great GW board for help! I'm new to the south and we're building a new home -- it's in the planning stages now. We're in southern Louisiana.

Should our attic (approx 1600 sq ft) have ventilation? One HVAC company we met with said we should just insulate the attic with open-cell foam, and not ventilate it at all. Our architect recommends a ridge vent or non-motorized wind turbine (those spinning mushroom vents). Because of our house's construction (right up against neighbors' walls), we can't do gable vents.

The roof material will be an asphalt shingle (medium grey). Various mechanical equipment will be in the attic, i.e. tankless water heater and heat-pump air handler.

Does anyone in hot-weather climates have a recommendation? Thanks in advance!