AHU air flow filter

[saeedplc]

Dear Experts,

Could you please let me know what parameters should I consider to order a new G4 filter for AHU.
Unfortunately there is no data on the current installed G4 filter.
Any relationship bettween AHU air flow m3/h and filter air volume?

Regards,

 

[LittleInch]

Differential pressure usually.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[saeedplc]

Thanks for your reply,

The filter air flow m3/h should be higher than or equal to AHU air flow m3/h? Because as far as I know final differential pressure of the filter is given in nominal flow of it so I should order a filter with a air flow equal or higher than AHU flow.
Am i correct?

 

[LittleInch]

Yes you are correct. At least equal to AHU flow.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[ChasBean1]

Filer airflow is the same is AHU airflow. Velocity is the key - size the filter bank large enough to be under about 500 fpm (~2.5 m3/s).

 

[SAK9]

Chasbean1 Long time no see! where have you been? Hope to see you here often!

 

[Compositepro]

500 fpm is 2.5 m/sec.

 

[SAK9]

Divide the AHU rated flow by the number of G4 filters you have now and that should give you air flow required per each G4 filter. That should be enough to order a new G4.

 

[ChasBean1]

SAK9, likewise, thank you! You and the crew of other usual suspects have been doing so well that I logged out and haven't been back on for a bit. Hope you are well! Odds are I won't have frequent logins but will stop in every now and then to stir the pot...

 

[quark]

Filters can take much higher velocities. 500 fpm is a spec for face velocity across coil to avoid condensate carry over and this applies to filters automatically as AHU cross section is same. G4 is pretty basic filter, so just check the CA and depth.