A damper comprising a frame, a first blade pivotally engaged with the frame, the first blade comprising a first end portion disposed at an obtuse angle α with respect to a first blade axis, the first blade comprising a hollow portion for receiving an insulating material and further comprising a first thermal gap for interrupting a thermally conductive path across the first end portion, a second blade pivotally engaged with the frame, the second blade comprising a second end portion disposed at an obtuse angle α with respect to a second blade axis, the second blade comprising a hollow portion for receiving an insulating material and further comprising a second thermal gap for interrupting a thermally conductive path across the second end portion, a first seal connected to the first end portion of the first blade, a second seal connected to the second end portion of the second blade, the first seal and the second seal disposed to cooperatively engage an adjacent first blade end portion and second blade end portion such that a dead air space is created between the adjacent first seal and second seal in a damper closed position, and the first thermal gap and the second thermal gap disposed within said dead air space in the damper closed position.