When a gas fired appliance is vented into a chimney flue serving an appliance which burns solid fuel in a commercial or industrial application, how shall the vent from the gas appliance be installed?

In the context of venting appliances, proper installation is crucial to ensure safe and efficient operation. When venting a gas-fired appliance into a chimney flue that is also serving an appliance burning solid fuel, it is important to maintain the integrity of each appliance's venting system to prevent backdrafts and ensure that combustion gases are properly expelled.

The correct option indicates that the vent from the gas appliance must be installed through a separate flue opening above the flue pipe connection of the solid fuel appliance. This approach helps to ensure that the gases from the gas-fired appliance have a clear passage to exit the chimney, minimizing the risk of contamination or backflow of flue gases from the solid fuel appliance into the gas appliance.

By installing above the other appliance’s connection, it prevents any potential interference from the flue gases of the solid fuel appliance which is critical for maintaining the operational safety of both systems. This configuration aligns with industry best practices and safety codes that dictate how different types of appliances should be vented to avoid dangerous scenarios such as carbon monoxide backdraft.

Overall, this setup ensures compliant venting that can effectively handle the byproducts of combustion from both types of fuel sources, thereby upholding safety and efficiency standards in commercial and industrial applications