Abstract: An apparatus for heat exchange between a heat source medium and a heat sink medium comprises a two-dimensional array of heat transferring individual modules. Each module comprises a header, an evaporator, extended from one side of the header into the heat source medium, and a condenser extended from another side of the header into the heat sink medium. The evaporator is located below the condenser and each one includes a U-shaped tube affixed to the header in a canted position. The module is charged with a heat transport medium existing in the module in both liquid and vapor phases. The heat transport medium within the evaporator receives a heat energy from the heat source medium and transports the received heat energy to the condenser, thereby cooling the heat source medium and thereby heating the heat sink medium.