What is the typical pressure for natural gas entering a furnace?

Natural gas typically enters a furnace at a pressure range of 5 to 7 inches of water column pressure. This pressure is sufficient to ensure that the gas can flow properly through the system and reach the burners effectively for combustion. It's important for the gas pressure to be within this range to maintain efficient operation and safety of the furnace.

If the pressure is too low, it may lead to inadequate gas flow, resulting in poor combustion and potential issues like sooting or incomplete burning of gas. On the other hand, if the pressure is too high, it may cause safety hazards and could damage the furnace components or lead to improper operation.

The other pressure ranges provided, while they are associated with different appliances or functions, do not reflect the typical operating pressure for natural gas entering a residential or commercial furnace. Therefore, 5 to 7 inches of water column pressure is the standard range recognized in the HVAC industry for this application.