Patent ID: 7866179

Claim:
A compact heat pump using water as refrigerant, comprising: a casing having a first end section and a second end section and an intermediate section located therebetween; an evaporator located at the first end section, configured for containing said water and allowing evaporation of at least a part of the water therefrom to produce vapor, thereby removing heat from the remainder of the water; at least one agitator scoop located within said evaporator, said scoop being used for both agitating and for spraying the water within the evaporator for increasing evaporation surface area; one or more demisters installed between the evaporator and the compressor, provided with a heating mechanism; one or more compressors located at the second end section and provided with an intake conduit extending from the evaporator to the compressor, configured to induce the evaporation by maintaining vacuum at least at the intake conduit, the compressor being further configured for receiving the vapor through the intake conduit after passing through the heated demister and compressing it; a condenser located in said intermediate section such that said intake conduit passes therethrough, said condenser being configured for receiving the compressed vapor from the compressor, lowering its temperature and condensing it back into a liquid state; and means to create and maintain vacuum in the casing.