Test B Note: In the following steps, the number n stands for the last digit of your student ID. For example, (50:n)%=52% if your student ID is 233242 and (50+n)%=50% if your student ID is 123450. In test B, the air flows through a recirculation duct. Close the Inlet Louvre and outlet Louvre, open Recycle Louvre fully. The system becomes an air recirculation system. Set the preheat control to (40+n)%. Wait until the temperatures are stabilized. Record the temperatures and flow velocities. Repeat the test by setting the preheat control to (50 -n)% and (60+n)%