Mac Air and the latest Samsung Series 9 laptops are very thin ultraportables that have the keyboard and CPU portion of the laptop almost as thin as the lid. Since this is a proof that this is technologically possible I believe it’s time laptop manufacturers look into eliminating lap heat by moving the main heat source(s) CPU (and the GPU) to the lid, thus also converting the entire back surface of the lid to a huge CPU heat sink.
Most laptop users who complain about warm laptops almost never touch the lid. They mind the warm bottom and noisy fans. By moving the CPU into the lid and making the back of the screen into a heat sink the machine wouldn’t need as much artificial air stream from a noisy fan because the air can usually circulate freely around the lid. As the air gets warmer, it rises and forms an upward stream that helps naturally exchange the heat – the higher the heat, the faster the air will flow even without a fan. In addition, any natural air stream around the laptop would help, and even if the laptop is closed, the hottest area is on top, which is the best way to cool it. This approach could finally eliminate both warm laps and noisy fans and make laptops more comfortable, cooler and quieter.