Which type of thermal storage units must also be listed and labeled under the code?

Pressurized thermal storage units are required to be listed and labeled under the North Carolina Mechanical Code due to safety and performance standards that must be met. These units store thermal energy under pressure, which can pose safety risks if proper construction and materials are not used. The listing and labeling process ensures that these units are evaluated by a recognized testing organization, indicating that they have met specific code requirements for safety and efficiency.

Having a listing label assures both installers and consumers that the product has been tested for reliability and adheres to the applicable standards, significantly reducing the risk of failure. Non-pressurized units, transportable units, and open-loop systems do not have the same inherent risks as pressurized systems and may not require this level of scrutiny under the code, therefore they do not need to be listed and labeled accordingly.