Re: [EnergyPlus_Support] Fan pressure rise question

["Michael J. Witte" <mjwitte@xxxxxxxx>]

In this case, it would be nice to be able to simply enter motor efficiency and 
total power input.  I will post a suggestion for that.  Looking in the 
Engineering Reference (p. 537, pdf p. 571), the equation for fan power for HVAC 
system fans (which is the same model used in the VENTILATION object) is:

Qtot[W]=mdot[kg/s]*deltaP[Pascals]/(TotalEfficiency*density[kg/m3])

or

Qtot[W]=VolumeFlow[m3/s]*deltaP[Pascals]/TotalEfficiency

(Note: Pascals=N/m2, so [N/m2]*[m3/s]=[N-m/s]=[J/s]=[W])

or

deltaP[Pascals] = Qtot[W]*TotalEfficiency/VolumeFlow[m3/s]


where TotalEfficiency is MotorEfficiency*FanEfficiency


MJW







On 30 Jan 2007 at 8:34, carlosochoam wrote:

> Dear all,
> 
> In the air flow object Ventilation, one of the required data to 
> determine electric energy consumption of the fan is the fan pressure 
> rise.
> 
> Is there a simple way to determine it? For example, for a fan that 
> could serve a room?
> 
> Thanks a lot,
> 
> Carlos
> 
> 
> 
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> 
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> 
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> 
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>  
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> 
> 
> 
> 
> 


========================================================
Michael J. Witte, GARD Analytics, Inc.
EnergyPlus Testing and Support      
EnergyPlus-Support@xxxxxxxx





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