Abstract: A vapor generating and recovery apparatus for generating a vapor from a liquid solution and recovering the vapor in a liquid form in at least one chamber of the apparatus, the vapor generating portion of the chamber being in heat emitting relation with a heat emitting means and the vapor recovering portion of the chamber being in heat absorbing relationship with a heat absorbing means. A preferred system for providing heat to the vapor generating portion of the chamber and removing heat from the vapor recovering portion of the chamber is a variable heat system which includes a main heat emitting means and a main heat absorbing means in heat transfer relation with the vapor generating and recovery chamber. The variable heat system further includes a complementary heat emitting means outside the chamber between the main heat emitting means and main heat absorbing means for removing excess heat from the heat transfer fluid leaving the vaporizing portion of the chamber.