Thermosyphons of the large length are of great interest for being used as heat exchangers for recuperation of alternative energy sources and upgrading their potential with the aid of heat pumps. Some examples of vapordynamic themosyphons (VDT) application as the system of thermal control for solar collectors, in the air conditioning systems, devices combating snow drifts and icing on the active parts of the railway transport track structure, foodstuff baking ovens and roasters, driers, etc. are considered. It is concluded that VDT used for air conditioning, ground heat exchangers, and seasonal thermal storage systems connecting with solar thermal collectors have good opportunities.