Did you check the spots where the crawl space walls meet the roof, to see whether there is a continuous unobstructed ventilation path, in each and every rafter bay, of at least 1 1/2 inches extending to the area above the room ceilings?
Did you check the installation of the ridge vents to ensure that the roof sheathing was cut away enough to allow hot air to exhaust? Is the ridge vent a metal external baffle type, or is it one of the worthless rolled ridge vents? The external baffle of a proper ridge vent creates a low-pressure area at the vent which helps exhaust hot air from the attic space.
Did you check the insulation values in the crawl space wall, and in the ceiling above the rooms?
Did you check where the crawl space floor insulation extends to the eaves to be sure that the insulation hasn't blocked the ventilation path, and that there is at least a 1 1/2 inch space above the insulation and into the crawl space?
It is neither rocket science nor wizardry. The questions I have asked reflect the fundamentals of roof ventilation, and the answer to your problem will be revealed by the answers to those questions.
Architect (NY) and Home Designer (PA)
