Rapid growth in the field of additive manufacturing has set off a stream ofresearch into complex shapes and geometries for engineering applications. Triply Periodic Minimal Surfaces (TPMS) are a class of differential surfaces that are gaining such increased interest in the past few years. Of the most commonly studied TPMS, Schwarz-D TPMS has been shown to out-perform traditional Heat eXchanger (HX) designs in recent research. This research examines some of the under-studied TPMS structures for HX applications. Fischer-Koch S, C(Y), and C(±Y) TPMS structures were numerically analyzed to predict their thermal-hydraulic performance and the results were compared with a Schwarz-D TPMS HX. The under-studied TPMS HXs showed a 1.5 to 5 times increase in overall thermal performance while maintaining similar pressure drops when compared to the Schwarz-D TPMS HX. Furthermore, thermal-hydraulic characterization of a full-scale TPMS based HX design was carried out for high temperature (> 900 °C) applications and a parametric HX design solver was developed to predict its performance within ±5% deviation.