18-29-607.2.1A Piping insulation.

   Piping in required return circulation systems shall be insulated to provide a thermal resistance, R, excluding film resistances, of

   R = [t1 - t0(hr)(Ft2)°F.]/Btu
      25

   For SI: R = [t1 - t0(0.0304)K x m2]/W

   where t1 - t0 is the design temperature differential between the water in the pipe and the surrounding air in degrees Fahrenheit (°F).

   Exception: Pipe insulation is not required where t1 - t0 is 25°F (14°C) or less.

(Amend Coun. J. 11-9-16, p. 36266, § 37)