Nozzle determination for Air Flow Test Chamber 1

[Kempenaar]

Hello,

Currently I'm designing a new measuring station to determine the air flow rate of an aircurtain.

In the standard 210 of AMCA Labroratory Methods of Testing Fans for Aerodynamic Performance Rating there are 3 different test methods that can work. These are Figure 11 Outlet Chamber Setup-Nozzle on End of Chamber and Figure 14 Inlet Chamber Setup-Ducted Nozzle on Chamber. And Figure 12 Outlet Chamber Setup-Multiple Nozzles in Chamber.
We like to choose for Figure 11 or 14 because they are excangeble.

The standard makes clear rules for the minimal velocity. Like under 5.3.2 Nozzles.
The average velocity at the nozzle discharge corresponding to the airflow rate at free delivery at the test speed is at least 14 [m/s]. But there are no clear limits for the maximum velocity other than a rule about settling means.

Is there anyone here having experience with testing according to the AMCA standard. Or has an idea what the velocity limit should be.

I need this do determine the range and number of nozzles I need to test air flow rates between 100 and 8500 cubic meters per hour.

Thanks in advance.

 

[MintJulep]

From ASHRAE 41.2, Standard Methods for Laboratory Airflow Measurements:

The throat velocity of any nozzle in use shall not be less than 3,000 fpm (15 m/s), nor more than 7,000 fpm (35 m/s).

 

[Kempenaar]

THX for the reply. Also found this on different sites.

The nozzle selection is based on a differential pressure between 0.1 inches w.g. and 4.0 inches w.g. The lower limit (0.1 inches w.g.) is used to ensure the flow in the nozzle is fully turbulent and the higher limit (4.0 inches w.g.) is used so compressibility is not a factor (4.0 inches w.g. is approximately 1% of an atmosphere).

Currently I'm contacting AMCA about this. Because I don't have a clue how you should measure or determine the flow settling means.