Author Question: What is the airflow through a 2 ft by 3 ft hole if the air velocity is 100 ft per minute? A) 100 ... (Read 158 times)

ahriuashd · **on:** Jul 24, 2018

What is the airflow through a 2 ft by 3 ft hole if the air velocity is 100 ft per minute?

A) 100 CFM B) 2 3 = 6 sq feet; 6 100 FPM = 600 CFM
C) 2 + 3 = 5 sq feet; 5 100 FPM = 500 CFM D) 2 3 = 6 sq feet; 100 FPM/6 = 17 CFM

Question 2

When is the gas valve energized on an induced-draft furnace that uses hot surface ignition?

A) After the draft switch closes to prove the draft
B) On the initial call for heat
C) After the igniter has been energized
D) At the same time the induced draft blower is energized