Metal hangar roof ridgeline vents - Open or closed?

[mshac]

If you had a fully-insulated metal hangar with ridge vents (roof vents), would it stay cooler in the summer with vents open or closed? This assumes the hangar door stays closed, of course.

My arguments for opening the vents would be airflow, removal of gases/odors, and moisture/rust control (mainly for the roof panels). But of course that air has to come from somewhere, so it causes negative pressure in the building which draws outside air into the interior.

My arguments for closing the vents would be to keep the cooler air inside the hangar.

I always keep vents closed in the winter, and the hangar remains reasonably warmer than the outside.

I've always kept the vents open in the summer months, but I wonder if it would actually keep it cooler if they were closed.

We're already into the low 90's here in Texas, so full-blown summer heat will soon be upon us!