Definition: A cubic meter per hour (m3/h) is a unit of volumetric flow rate representing one cubic meter of substance passing a point in one hour. It is used to measure smaller volumes of fluid or gas flow compared to m3/min or m3/s, but over a longer period.

History/origin: Based on the cubic meter as the unit of volume, and 'per hour' denoting the time frame. The unit's creation addresses the need for quantifying lower flow rates in various industrial and environmental applications.

Current use: M3/h is common in heating and cooling systems, small-scale industrial processes, and in monitoring environmental parameters where slower rates of flow are typical. Examples include measuring gas consumption in households, flow rates in chemical processing and measuring the flow of water in heating systems.