Presents a procedure for measuring the volume flow rate of air through a heating or cooling coil. States that when a pitot tube traverse is impossible or impractical, the rotating vane anemometer procedure which is described and verified, will provide volume flow rates with similar uncertainty in the results. Shows that the procedure produces estimates of volume flow rate at coil faces to within 7%. States the procedure is valid in a velocity range of 100 to 1100 fpm, and upstream disturbances such as elbows, partially blocked coils, dampers and fan blasts had virtually no effect on the accuracy of using the K-factor procedure as long as the measured velocities were positive and relatively uniform.

KEYWORDS: Air flow, heating coils, cooler batteries, measuring, anemometers, accuracy.