Natural gas flow rate: Nm³/h, m³/h and what they mean in practice

Natural gas flow rate can be expressed in m³/h or Nm³/h. The two units are similar but not always numerically identical.

m³/h

Refers to the actual volume of gas at the pressure and temperature conditions of the measurement point.

Nm³/h

Refers to the volume normalized to defined reference conditions. This allows for the comparison of measurements taken under different conditions.

Why it is important

When selecting a meter, regulator, or burner, it is necessary to know whether the flow rate refers to actual or standard conditions.

Relation to power

The required flow rate depends on the power output of the burner and the calorific value of the gas.