Flow Hood for Measuring Airflow From Ceiling Diffusers
2.21 TEST PROCEDURE. Testing and balancing of a mechanical ventilating
system is necessary to insure proper operation. The most common complaints
from occupants who are too hot or too cold are frequently traced to an air
system which is not balanced properly.
At the time of initial installation of the duct system, the design data
should be recorded. After initial start-up, balance the system so that each
air outlet is adjusted to deliver its rated cfm. After the system is bal-
anced, take static pressure measurements at the fan inlet and outlet, and at
the inlet and outlet of each coil or filter. This data may be used as ref-
erence data for future troubleshooting. By comparing measurements at a
future date to the original measurements, the maintenance technician may
determine if problems are due to equipment or if occupants in the building
have taken it upon themselves to rebalance the system.