The present invention relates to a modular reciprocating panel system designed to support capillary hydronic mats used in building conditioning. The invention features an encapsulated capillary mat comprising three layers: a first metal layer with machined grooves, a second layer consisting of a capillary mat with parallel tubes and manifold tubes, and a third layer with a planar surface. These layers are thermally interconnected to enhance heat transfer efficiency. An exemplary capillary mat is encapsulated between the first and third layers, which are in thermal communication. The invention also includes a spigot system for secure connection of the manifold tubes, enabling fluid communication between reciprocating panels arranged in an array. This system provides improved thermal radiant capacity and uniform panel surface temperatures, optimising energy transfer for building conditioning.