2021 Uniform Mechanical Code Updates for Air and Gas Ducts

The 2021 version of the Uniform Mechanical Code (UMC®) represents probably the most present approaches within the mechanical subject. It’s the seventh version developed underneath the ANSI Consensus course of is designated as an American Nationwide Requirements by the American Nationwide Requirements Institute (ANSI). Moreover, it addresses particular provisions for low flammability refrigerants comparable to A2L and B2L; which makes it one of many first codes within the trade to handle particular provisions for these low International Warming Potential (GWP) refrigerants. Contributions to the content material of this code have been made by each section of the constructed trade, together with such various pursuits as shoppers, imposing authorities, installers/maintainers, labor, producers, analysis/requirements/ testing laboratories, particular consultants and customers.

The 2021 UMC introduces several key changes to heating, ventilating, cooling, and refrigeration systems. These updates include new Appendix F for Geothermal Power Systems, as well as requirements for guards and rails on roofs and ventilation in both transient and nontransient occupancies. Additionally, revisions have been made to air duct and dampers regulations, with new provisions for factory-built grease ducts and refrigeration systems. The UMC now includes sizing requirements for natural gas and propane piping systems, as well as new provisions for hydronic piping applications. Gas fuel piping equipment now has updated safety requirements, while tube fastener provisions for radiant heating and cooling systems have also been added. Other notable changes cover residential compressed natural gas fueling systems and requirements for fire-extinguishing equipment and carbon monoxide detection in exhaust systems.