What material should hangers and brackets for suspended-type unit heaters be made from?

Hangers and brackets for suspended-type unit heaters should be made from noncombustible material to ensure safety and compliance with the International Mechanical Code (IMC). The use of noncombustible materials is crucial because unit heaters can generate significant heat during operation, and materials that could catch fire or degrade under high temperatures would pose a safety risk. Using noncombustible materials reduces the likelihood of fire hazards and ensures that the support structures can withstand the operational conditions of the heaters over time.

Noncombustible hangers and brackets also contribute to the durability and stability of the installation, reducing the risk of structural failure or damage. This aligns with the code's emphasis on maintaining safety standards in mechanical system installations. In contrast, materials like wood and plastic may not only be combustible but might also not provide the necessary strength and durability required for supporting heating equipment. Combined metals, while potentially sturdy, may still incorporate materials that do not meet the noncombustibility criterion, making them a less favorable option. Therefore, noncombustible materials are the most appropriate choice for ensuring safety and compliance in the installation of suspended-type unit heaters.