Some modular heat-transfer systems can have an array of at least one heat-transfer element being configured to transfer heat to a working fluid from an operable element. A manifold module can have a distribution manifold and a collection manifold. A decoupleable inlet coupler can be configured to fluidicly couple the distribution manifold to a respective heat-transfer element. A decoupleable outlet coupler can be configured to fluidicly couple the respective heat-transfer element to the collection manifold. An environmental coupler can be configured to receive the working fluid from the collection manifold, to transfer heat to an environmental fluid from the working fluid or to transfer heat from an environmental fluid to the working fluid, and to discharge the working fluid to the distribution manifold.