What is the insulation in the roof vents intended to be for ... to 1) keep the cool air conditioned air from escaping the living area, or to 2) keep the hot air from the outside from getting into the living area, or to 3) keep the sun from heating up the vent and thus heating the air in the living area?
It it's 1) ... cool air doesn't rise anyway. If it's 2) ... how can hot outside air get in a closed vent regardless of any insulation? If it's 3), will vent covers shade the vents such that the sun can't heat up the vent?
We have vent covers over all vents, and I'm wondering if and why the vent insulation is needed.