Apparatus for downward transport of heat

An apparatus for the downward transport of heat by vaporization of a working fluid, usually from a collector which can be powered by the Sun to a condenser which drains the condensed working fluid to a lower reservoir, is controlled by a control valve which is operationally dependent upon the level of working fluid in either the lower reservoir or an upper reservoir which feeds the collector. Condensed working fluid is driven from the lower to the upper reservoir by vaporized working fluid whose flow is controlled by the control valve. The upper reservoir is in constant communication with the condenser which prevents a buildup in temperature/pressure as the apparatus goes through successive pumping cycles.