1707.7 Ground-Heat Exchanger Installation Practices — 2025 California Mechanical Code

1707.7 Ground-Heat Exchanger Installation Prac- tices. A ground-heat exchanger system shall be installed as follows:

(1) Outside piping or tubing located within 5 feet (1524 mm) of any wall or structure shall be continuously insulated with insulation that has a minimum R-5 value. Such pipe or tubing installed under the slab or basement floors shall be insulated within 5 feet (1524 mm) from the structure to the exterior point of exit from the slab.

(2) Freeze protection shall be provided where the design of the ground-heat exchanger system would permit the heattransfer medium to freeze.

(3) Horizontal piping shall be installed not less than 12 inches (305 mm) below the frost line.

(4) Submerged heat exchangers shall be protected from damage and shall be securely fastened to the bottom of the lake or pond, or other approved submerged structure.

(5) A minimum separation distance shall be maintained between the potable water intake and the submerged heat exchanger system in accordance with the Authority Having Jurisdiction.

(6) Vertical and horizontal ground-heat exchangers shall maintain the following setbacks:

(a) Ten feet (3048 mm) horizontally from a pressuretested sewer lateral into a building.

(b) Twenty feet (6096 mm) horizontally from a nonpressure tested sewer lateral into a building.

(c) Three feet (914 mm) horizontally from buried utilities such as electrical, gas, or water.

(d) Fifty feet (15 240 mm) from a water well.

(e) Fifty feet (15 240 mm) from a septic tank and 100 feet (30 480 mm) from a subsurface sewage leaching field.

(f) One hundred feet (30 480 mm) from a spring; or at distances specified by the Authority Having Jurisdiction.

(7) Wells and boreholes shall be sealed in accordance with the Authority Having Jurisdiction. Where grout is required, it shall be applied in a continuous operation from the bottom of the borehole by pumping through a tremie pipe.