ABSTRACT
Testing and balancing is the measurement of air volumes and adjusting volume control devices to get the desired airflow. This chapter explains the procedure to determine the airflow quantity in the supply air, return air, outside air, and exhaust air duct distribution systems. Begin the testing of the air distribution system by setting the automatic temperature controls on full cooling. The pressures measured at the fan and air handling unit, and the air distribution duct systems are total pressure, static pressure, and velocity pressure. A Pitot tube traverse of the duct is needed to determine the average velocity in the duct at the point of traverse. To do a Pitot tube traverse of a square or rectangular duct, determine the number and distance of the holes in the duct and the markings on the Pitot tube. After the location for a round duct Pitot tube traverse has been determined, drill two holes in the duct 90 degrees apart.
