A hot/cold aisle air containment room includes a plurality of electronic equipment enclosures at least partially defining an interior aisle, a frame structure supporting one or more ceiling panels above the interior aisle, and a door assembly. The door assembly includes a sliding door and an unpowered door closer mechanism adapted to move the sliding door from an open state to a closed state, thereby providing controlled access to the interior aisle and minimizing intermixing of hot air and cold air between an environment external to the hot/cold aisle air containment room and an environment internal to the hot/cold aisle air containment room.