In the framework of human space flight, the active control of temperature inside crewed modules assumes paramount importance in protecting the habitable environment from the harsh thermal conditions of outer space. The need to actively remove the heat from the module is met through suitably sized heat exchangers, as part of the Active Thermal Control Subsystem (ATCS). This study carried out in collaboration with Thales Alenia Space Italia, concerns the conceptual design of a Triply Periodic Minimal Surfaces (TPMS) Compact Heat Exchanger (CHX), for space applications, to be used with two streams of 3M Novec HFE 7200 DL in the temperature range from -50 to 6.5 °C.