"cfh" stands for cubic feet per hour. It is a unit of volumetric flow rate used to measure the volume of gas that passes through a specific point in a given timeframe.

Here's a breakdown:

* Cubic feet (cf): This refers to the volume of gas measured in cubic feet.

* Per hour (h): This indicates that the flow rate is measured over a one-hour period.

Example:

If a natural gas furnace is rated at 100,000 cfh, it means that it consumes 100,000 cubic feet of natural gas per hour.

Important Note:

While cfh is a common unit for gas flow rate, it's crucial to remember that it only measures the volume of gas and not its energy content. To express the energy content of gas, you would use units like BTUs per hour (BTU/h).