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Re: [EnergyPlus_Support] Fan Pressure Rise for a PTAC





Jim,

Thank you very much for your quick and clear reply.
I ve got one more question. Do you know where I can find a table with fan efficiency values for typical applicarions such as PTAC, package rooftops, etc.

Kind Regards,

Felipe Durán Palma
Arquitecto UC, MPhil. U. Cambridge, LEED AP BD+C
Gerente de Proyectos
B-green Chile S.A.


El 24-08-2012, a las 14:07, Jim Dirkes <jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx> escribió:

 

Felipe,

I am unfamiliar with the calculation in SI units, but recommend that you refer to a text such as the ASHRAE Handbook of Fundamentals.

For IP / US units, it looks like:

<image001.png>

 

You will need to determine the fan efficiency (â??ηâ?? in the equation above).  For the small fan you are using, it is probably in the range 20-40%.

For a PTAC, pressure rise is normally in the range 0.20 ? 0.50 inches water column  (50-125 PPascals)

 

James V Dirkes II, PE, BEMP, LEED AP
www.buildingperformanceteam.com

Energy Analysis, Commissioning & Training Services
1631 Acacia Drive, Grand Rapids, MI 49504 USA
616 450 8653

 

From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Felipe Durán
Sent: Friday, August 24, 2012 1:11 PM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] Fan Pressure Rise for a PTAC

 

 

Dear All,

I am wondering how to calculate the fan pressure rise for a PTAC. The max. flow rate is 0,16 m3/s = 339 CFM x 0,3 = 101 W.

Since I ve got the fan power (101 W) and the max flow rate (0,16 m3/m) ¿Does anybody knows how to calculate the fan pressure rise?

Kind Regards,

Felipe Durán Palma
Arquitecto UC, MPhil. U. Cambridge, LEED AP BD+C
Gerente de Proyectos
B-green Chile S.A.



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