The energy efficient heat pump drying, often referred to as de-humidification drying, is basically a simple concept, in which the heat pump derives its heat energy from solar radiation and the refrigeration process at 4 to 5 times the consumed power. This heat is directed into the to a sealed and insulated chamber containing the material to be dried. No heat is lost during the drying cycle the air contained in the drying chamber is recirculated through an dehumidifying (cooling) coil and reheated by the condenser (heating) coil. Temperature and humidity controllers maintain conditions for optimal drying operation. The air in the chamber circulates again through the evaporator coil, and is cooled on the face of the coil, and the circulating air, unable to contain the same percentage of moisture as when heated, precipitates the moisture on the coil and subsequently drains to waste.

No heat or energy is lost as only product water leaves the chamber.