Patent ID: 7593229

Claim:
An apparatus comprising: a heat exchange structure comprising elongated air ducts, each air duct having a first opening and a second opening at two ends of the air duct to allow air to enter and exit the air duct, respectively, the heat exchange structure comprising an exterior heat exchange surface and interior heat exchange surfaces, the exterior heat exchange surface configured to receive thermal energy from heat generators that are mounted on the exterior heat exchange surface, the exterior heat exchange surface dissipating a portion of the thermal energy received from the heat generators and transferring another portion of the thermal energy to the interior heat exchange surfaces, the interior heat exchange surfaces being in the elongated air ducts and configured to exchange thermal energy with air flowing in the air ducts, enhancing air flow in the air ducts by buoyancy of heated air, the heat exchange structure further comprising a structural section and a thin layer of ceramic material attached to a surface of the structural section, the thin layer of ceramic material having a thickness less than 100 μm, wherein the thin layer of ceramic material comprises a first sub-layer that is substantially impermeable to air molecules and a second sub-layer that is at least partially permeable to air molecules.