An installation tool for installation of earth loops includes a cylindrical body with slots in its outer surface, for receiving of tubes of the earth loops, and a central passage extending therethrough from a grout fitting to a central opening at a leading end face of the cylindrical body. An anchor fits over the end face and includes a face plate with tube apertures extending therethrough, a retainer ring which serves to hold the earth loops in place within the slots during insertion of the tool into the borehole, and a pair of flexible plates extending from opposing positions on the retainer ring, approximately in parallel with the longitudinal axis of the cylindrical body. In use, a plurality of straight (linear) boreholes are drilled at an angle relative to the horizontal of 5° to less than 90°, preferably 5° to 45°, at least two coupled tube pairs are inserted into each borehole and then grout is injected to force the anchor away from the cylindrical body, to fill the boreholes surrounding the earth loops and to form a seal for heat exchange between the earth loops the surrounding earth.