What is the typical gas pressure required at the manifold and burners in natural gas furnaces?

In natural gas furnaces, the typical gas pressure required at the manifold and burners is approximately 3.5 inches of water column (WC). This pressure is essential for ensuring that the gas is delivered efficiently and effectively into the combustion chamber to maintain proper combustion and optimal furnace function.

Operating at this pressure allows the burners to perform efficiently, producing the right amount of heat while minimizing incomplete combustion and reducing the production of harmful byproducts like carbon monoxide. Proper gas pressure is also critical for the safety and longevity of the furnace, as it helps prevent issues such as burner flame instability and system strain.

In the context of furnace operation, pressures that are too low can lead to insufficient heating and may cause irregular burner operation, whereas pressures that are too high can pose safety risks and could lead to equipment damage. Therefore, a manifold pressure of 3.5 inches of WC is the standard that balances performance and safety in natural gas systems.