A method for installation of heat exchanger of heat pump unit with return hydraulic cycle includes laying to cavity formed in earth a pipe made of heat-conductive thermoplastic form of which provides possibility of passage of liquid heat carrier through its cavity and formation of inlet and outlet contours of heat exchanger. The pipe made of heat conductive thermo-plastic is lowered to the cavity in earth formed for making deep to earth building support construction through filling cavity with concrete mix to obtain heat conductive concretes. The pipe made of heat-conductive thermo-plastic is placed in such way that its part is placed lower than level of surface of earth, and openings of both ends of the pipe are placed out of part of surface of building support structure that is not in contact with earth with provision of possibility of connection to heat pump unit with reverse hydraulic cycle. The pipe made of heat-conductive thermo-plastic is placed in such way that its placement in the body of building support construction provides protection of pipe against direct contact with earth that surrounds building support structure.