In recent years the development of electronic devices has gone from increasing processor frequency and minimizing the size of the circuits to new methods to cool down the devices. For the moment the bottleneck lies in the cooling of both processors and memories. Especially for workstations, laptops, tablets and mobile phones that also need to be quiet and have a low external temperature. Fraunhofer-Chalmers research centre has developed a state-of-the-art flow solver called IPS IBOFlow. The conjugated heat transfer module in IPS IBOFlow is developed to simulate cooling of electronic devices such as computers and mobile phones. The module handles fans, porous media, natural convection, IC resistors and thin thermal interfaces.