Which unit is used to measure home gas pressure?

Which unit is used to measure home gas pressure?

• A. psi
• B. kPa
• C. bar
• D. inches water column

Answer: (D)

Gas systems in homes operate at very low pressures, so the standard way to express pressure is as a height of a water column. Inches of water column is practical because tiny pressure differences map directly to small changes in the height of a water column, which is easy to read with simple tools like manometers and regulators used on gas lines and appliances. For perspective, a small change in inches of water column corresponds to a tiny change in pressure (about 0.036 psi per inch of water), which matches how low residential gas pressures are. Using psi or metric units would yield awkwardly small or large numbers for typical home pressures, so inches water column is the conventional unit for measuring home gas pressure.

Gas systems in homes operate at very low pressures, so the standard way to express pressure is as a height of a water column. Inches of water column is practical because tiny pressure differences map directly to small changes in the height of a water column, which is easy to read with simple tools like manometers and regulators used on gas lines and appliances. For perspective, a small change in inches of water column corresponds to a tiny change in pressure (about 0.036 psi per inch of water), which matches how low residential gas pressures are. Using psi or metric units would yield awkwardly small or large numbers for typical home pressures, so inches water column is the conventional unit for measuring home gas pressure.