In the example, which gas-quantity option is listed for a 250 MBH appliance input?

• A. 100 cf of c3h8
• B. 3360 cf T.C.A
• C. 250 cf of ch4
• D. 2500 cf T.A.

Answer: (B)

Think of the appliance’s 250 MBH rating as a heat-output figure and the gas quantity as how much gas (in cubic feet) must flow to supply that heat, using a standard reference for conditions. The problem uses a temperature- and pressure-corrected standard (T.C.A) for gas volume. Under that convention, the amount of gas corresponding to a 250 MBH input is listed as 3360 cubic feet, corrected to temperature and pressure (T.C.A). This choice matches the specific correction method the example employs, so it’s the best fit.

The other options don’t align with the same correction method or the same gas-volume convention used in the example, so they don’t correspond to the 250 MBH input under the same standard.