Energy efficient dialysis system

A method of conserving energy in a dialysis system having fluid inlet means for causing a flow of washing fluid, a reverse osmosis machine receiving said flow of washing fluid and having a membrane operable at a first given temperature to filter said washing fluid and discharge impurities therefrom in a discharge stream, at least one kidney machine receiving the filtered washing fluid from said reverse osmosis machine and having a membrane operable to remove contaminants from a body fluid by entraining said contaminants in said flow of washing fluid at a second given temperature, heating means adjacent the entry of said kidney machine to change the temperature of said filtered washing fluid from said first given temperature to said second given temperature, and means to control the temperature of the washing fluid entering the reverse osmosis machine at said first given temperature;

• the steps comprising providing heat exchange means, directing the discharge streams from said reverse osmosis machine and said kidney machine into said heat exchange means, introducing fresh washing fluid through said heat exchanger to recover heat energy from said discharge streams to preheat the washing fluid, and introducing said preheated washing fluid into said fluid inlet means to obtain washing fluid at said first given temperature for being received into said reverse osmosis machine.