Which type of venting is allowed for appliances where ducts penetrate ceiling membranes?

The correct answer is the use of sealed connections with noncombustible materials. This approach is essential in ensuring that the venting systems for appliances maintain both safety and efficiency. When ducts penetrate ceiling membranes, it is critical to use materials that can withstand high temperatures without the risk of combustion. Noncombustible materials provide a reliable barrier against fire hazards, which is crucial in locations where the ducts may come into contact with combustible structures.

This practice aligns with safety codes and guidelines that govern the installation and maintenance of HVAC systems. It helps prevent the spread of flame and ensures that the ducting is adequately sealed to minimize the risk of fire and improve the overall performance of the venting system. Additionally, using noncombustible materials enhances the longevity and durability of the connections by reducing the likelihood of deterioration associated with heat exposure.

By employing this method, compliance with the North Carolina Mechanical Code is achieved, resulting in a safer environment and more effective appliance operation.