To convert Btu per hour to CFM per minute, take the energy transfer rate in Btu and divide it by 100,000. Multiply the result by 96.7. Divide that result by 60 to devise the gas transfer rate in cubic feet per minute.
The Btu has to be divided by 100,000 because that is the number of Btu in a therm. A therm of gas has a volume of 96.7 cubic feet. This number is sometimes roughly estimated to be 100 cubic feet rather than the more specific 96.7 cubic feet because it is typically an easier number to utilize in mathematical equations, though the resulting number would be more of an estimate rather than an actual result. The result of that equation is divided by 60 because that is the number of minutes in an hour. It is possible to convert between Btu and CFM because the energy of the gas is equal to the gas's volume.
The therm is the most common unit of measurement for natural gas. Btu are used once the amount of therms climbs above 100,000. In addition to being equal to 100,000 therms, the Btu is equal to 105.5 megajoules and 29.3 kilowatt-hours of energy.