Abstract: A method and apparatus for heat and mass transfer is described that is applicable to: concentration, crystallization, purification, fractionation, stripping, absorption, and/or heat exchange for liquid media; drying for solid or gel media; and temperature and humidity modification for gas media. Generally, using a moving gas, such as air at a constant and atmospheric pressure, a continual change in a vapor-liquid equilibrium is created between proximate but continually changing gas and liquid temperatures within energy transferring chambers. Chamber wetting, implemented segmentedly, allows mass transfer into and from the moving gas. A forced temperature differential in each chamber causes heat transfer between chambers by means of thermally conductive partitions. This transfer can allow condensation causing further evaporation in the opposite chamber resulting in a recycling of energy.