Which type of gas has an operating pressure of 11.0 inches of water column?

The correct answer is LP gas. LP gas, or liquefied petroleum gas, typically has an operating pressure that can be around 11.0 inches of water column (WC). This value is important in ensuring that appliances designed for LP gas operate correctly and efficiently, as gas pressures that are too low or too high can lead to poor combustion and reduced appliance performance.

Natural gas generally has a lower pressure, often ranging from 3.5 to 7 inches of water column, and operates at a different pressure than LP gas. Propane and butane are components of LP gas, but they are usually referenced in terms of their containment and handling specifications, where they can be stored at much higher pressures than what is indicated for the operational use in appliances. Understanding the correct pressures for these gases is critical for proper installation and safety in HVAC systems.