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Re: [EnergyPlus_Support] Re: Fan Power Pressures and Efficiencies - Are the calculations based on Pstat or Pt
The value you enter in the fan object is used by E+ in the calculations:
the equations are described in the Engineering Reference. The detlaP
used in those equations are the value you enter in the fan object (in
this case 600 Pa)
Fan:OnOff,
Supply Fan 1, !- Name
FanAndCoilAvailSched, !- Availability Schedule Name
0.7, !- Fan Efficiency
600.0, !- Pressure Rise {Pa}
jeannieboef wrote:
>
> Correct, however still not clear which is used as user input and which
> is calculated by e+.
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com>, Richard Raustad
> <RRaustad@...> wrote:
> >
> > Total pressure.
> >
> > Ptotal = Pstatic + Pdynamic
> > Ptotal = Pstatic + 1/2 * rhoV^2
> >
> >
> > jeannieboef wrote:
> > >
> > > Are the calculations based on total pressure or static pressure rise?
> > >
> > > Field: Supply Fan Total Efficiency
> > > Enter the total efficiency of the supply fan. This is the ratio of
> the
> > > power delivered to the air to
> > > the electrical input power at maximum flow. This is also the product
> > > of the fan motor
> > > efficiency and fan (impeller) efficiency. The motor efficiency is the
> > > power delivered to the
> > > shaft divided by the electrical power input to the motor. The fan
> > > efficiency is the power
> > > delivered to the air divided by the shaft power. The power delivered
> > > to the fluid is the mass
> > > flow rate of the air multiplied by the pressure rise divided by the
> > > air density. Must be greater
> > > than 0 and less than or equal to 1. The default is 0.7.
> > >
> > > Field: Supply Fan Delta Pressure
> > > Enter the pressure rise in Pa at full flow and standard conditions.
> > > Standard conditions are
> > > considered 20o C at sea level, 101325 Pa. The default is 1000 Pa.
> > >
> > >
> >
> > --
> > Richard A. Raustad
> > Senior Research Engineer
> > Florida Solar Energy Center
> > University of Central Florida
> > 1679 Clearlake Road
> > Cocoa, FL 32922-5703
> > Phone: (321) 638-1454
> > Fax: (321) 638-1439 or 1010
> > Visit our web site at: http://www.fsec.ucf.edu <http://www.fsec.ucf.edu>
> >
> > UCF - From Promise to Prominence: Celebrating 40 Years
> >
>
>
--
Richard A. Raustad
Senior Research Engineer
Florida Solar Energy Center
University of Central Florida
1679 Clearlake Road
Cocoa, FL 32922-5703
Phone: (321) 638-1454
Fax: (321) 638-1439 or 1010
Visit our web site at: http://www.fsec.ucf.edu
UCF - From Promise to Prominence: Celebrating 40 Years
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