Photo Source: Summerhill

Photo Source: Summerhill

9.36.2.5. (6) Where mechanical, plumbing or electrical system components, such as pipes, ducts, conduits, cabinets, chases, panels or recessed heaters, are placed within and parallel to a wall assembly required to be insulated, the effective thermal resistance of that wall at the projected area of the system component shall be not less than that required by Tables 9.36.2.6.A, 9.36.2.6.B, 9.36.2.8.A and 9.36.2.8.B

A-9.36.2.5. (6) Effective Thermal Resistance at Projected Area . Sentence 9.36.2.5.(6) does not apply to components that completely penetrate the building envelope, such as air intake or exhaust ducts. However, it does apply to components that are installed within or partially within the building envelope but that don't penetrate to the outdoors, and to any piece of equipment that is merely recessed into the wall.