If the test dial reads 3 cubic feet in 15 seconds, what Btuh value does this correspond to?

If the test dial reads 3 cubic feet in 15 seconds, what Btuh value does this correspond to?

• A. 90,000 Btuh
• B. 360,000 Btuh
• C. 270,000 Btuh
• D. 180,000 Btuh

Answer: (C)

This tests converting a gas flow rate into an energy rate (Btuh) by using the gas’s energy content per cubic foot. First find the hourly volume: 3 cubic feet in 15 seconds equals 3 × (60/15) = 12 cubic feet per minute, and 12 × 60 = 720 cubic feet per hour. Then multiply by the energy content per cubic foot (375 Btu/ft^3 in this problem): 720 × 375 = 270,000 Btuh. So the test dial flow corresponds to 270,000 Btuh.

This tests converting a gas flow rate into an energy rate (Btuh) by using the gas’s energy content per cubic foot. First find the hourly volume: 3 cubic feet in 15 seconds equals 3 × (60/15) = 12 cubic feet per minute, and 12 × 60 = 720 cubic feet per hour. Then multiply by the energy content per cubic foot (375 Btu/ft^3 in this problem): 720 × 375 = 270,000 Btuh. So the test dial flow corresponds to 270,000 Btuh.