A projection apparatus includes an outer casing, a light source disposed within the casing for generating light beams, and an optical engine connected to the light source for receiving the light beams in order to project an image. A heat sink includes an air tunnel mounted within the casing, and having air inlet disposed above the light source, and an exhaust fan mounted within an opening unit in the casing such that the fan unit is disposed in alignment with an air outlet of the air tunnel to transmit the intensive heat generated from the light source.