# 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 DurÃ¡n PalmaArquitecto UC, MPhil. U. Cambridge, LEED AP BD+CGerente de ProyectosB-green Chile S.A.El 24-08-2012, a las 14:07, Jim Dirkes escribiÃ³: 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: You will need to determine the fan efficiency (â??Î·â?? 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 APwww.buildingperformanceteam.com Energy Analysis, Commissioning & Training Services1631 Acacia Drive, Grand Rapids, MI 49504 USA616 450 8653 From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Felipe DurÃ¡nSent: Friday, August 24, 2012 1:11 PMTo: EnergyPlus_Support@xxxxxxxxxxxxxxxSubject: [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) Â¿Does anybody knows how to calculate the fan pressure rise?Kind Regards,Felipe DurÃ¡n PalmaArquitecto UC, MPhil. U. Cambridge, LEED AP BD+CGerente de ProyectosB-green Chile S.A. __._,_.___ Primary EnergyPlus support is found at: http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx The primary EnergyPlus web site is found at: http://www.energyplus.gov The group web site is: http://groups.yahoo.com/group/EnergyPlus_Support/ Attachments are currently allowed but be mindful that not everyone has a high speed connection.  Limit attachments to small files. EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button. Your email settings: Individual Email|Traditional Change settings via the Web (Yahoo! ID required) Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe __,_._,___