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Re: [EnergyPlus_Support] Re: Help with override error





Does your input file include report variables for inlet air T and W, air flow rate, coil cooling rate, etc. to use for debugging? Have you checked the eio file for any indications of size of this coil? Being a developer, I typically do not run files posted on the yahoo groups web site since this is a peer-to-peer site.

On 8/3/2011 9:50 AM, Jean marais wrote:
 

Hi Richard,I now specified both and the error went away, but now I get garbage comming out with humidities of zero instead of close to 100%. I'm putting the 20110721.epmidf.zip in the problem files area.

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad <RRaustad@...> wrote:
>
> This probably relates to your problem. You tell the program to chose the
> inlet air humrat, but then specify the outlet air humrat.
>
> autosize, !- Design Inlet Air Humidity Ratio {kg-H2O/kg-air}
> 0.0010, !- Design Outlet Air Humidity Ratio Entering is 0.01178 ,0.0050
> does not work
>
> I would run the program for the sizing period and report the outdoor T
> and W to see how these values change. That warning looks like one that
> should provide more information. Alternately you could specify both or
> autosize both.
>
> On 8/3/2011 8:52 AM, Jean marais wrote:
> >
> > Hi Richard,
> >
> > I've set the coil and it was working until I upped the entering
> > humidity. I now get:
> > ** Warning ** SizeWaterCoil: Coil="DOAS COOLING COIL", Cooling Coil
> > has leaving humidity ratio > entering humidity ratio.
> > ** ~~~ ** ..will be sized for 50% of entering humidity ratio.
> >
> > EVENTHOUGH entering air from outside has humidity of 0.01178 and the
> > coil is set to 0.001.
> >
> > SizingPeriod:DesignDay, Summer Design Day in BBI Terminal, !- Design
> > Day Name
> > 32.0, !- Max Dry-Bulb {C}
> > 10.3, !- Daily Temp Range {C}
> > 0.01178,!21.74, !- Wet-Bulb at Max {C} gH2O/gDryAir
> > 100761.7, !- Barometric Pressure {N/M**2}
> > 0, !- Wind Speed {m/s}
> > 0, !- Wind Direction {Degrees N=0, S=180}
> > 0.98, !- Clearness {0.0 to 1.1}
> > 0, !- Rain {0-no,1-yes}
> > 0, !- Snow on ground {0-no,1-yes}
> > 15, !- Day of Month
> > 7, !- Month
> > SummerDesignDay, !- Day Type -- used for schedules
> > 1, !- Daylight Savings Time Indicator
> > HumidityRatio,!WetBulb, !- Type of humidity temperature Indicator
> > , !- Relative Humidity Day Schedule(not used)
> > , !- Dry-Bulb Temperature Range Modifier Type (not used)
> > ; !- Dry-Bulb Temperature Range Modifier Schedule (not used)
> >
> > Coil:Cooling:Water,
> > DOAS Cooling Coil, !- Name
> > 2, !- Availability Schedule Name
> > autosize, !- Design Water Flow Rate of Coil {m3/s}
> > autosize, !- Design Air Volume Flow Rate {m3/s}
> > 6,!autosize, !- Design Inlet Water Temperature {C}
> > 32,!autosize, !- Design Inlet Air Temperature {C}
> > 18,!autosize, !- Design Outlet Air Temperature {C}
> > autosize, !- Design Inlet Air Humidity Ratio {kg-H2O/kg-air}
> > !autosize, !- Design Outlet Air Humidity Ratio {kg-H2O/kg-air}
> > 0.0010, !- Design Outlet Air Humidity Ratio Entering is 0.01178
> > ,0.0050 does not work
> > DOAS Cooling Coil ChW Inlet, !- Coil Water Inlet Node
> > DOAS Cooling Coil ChW Outlet, !- Coil Water Outlet Node
> > DOAS Mixed Air Outlet, !- Air Inlet Node Name
> > DOAS Cooling Coil Air Outlet, !- Air Outlet Node Name
> > DetailedAnalysis, !- Type of Analysis
> > CrossFlow; !- Heat Exchanger Configuration
> >
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> > <mailto:EnergyPlus_Support%40yahoogroups.com>, "Jean marais"
> > <jeannieboef@> wrote:
> > >
> > > I have the following error:
> > >
> > > ************* Beginning System Sizing Calculations
> > > ************* Beginning Plant Sizing Calculations
> > > ** Warning ** In calculating the design coil UA for
> > Coil:Cooling:Water DOAS COOLING COIL
> > > ** ~~~ ** the apparatus dew-point is below the coil design inlet
> > water temperature;
> > > ** ~~~ ** the coil bypass factor is unrealistically large;
> > > ** ~~~ ** the coil outlet design conditions will be changed to
> > correct the problem.
> > > ** ~~~ ** The initial design conditions are: Tair,in = 24.4500
> > > ** ~~~ ** Wair,in = 9.478796E-003
> > > ** ~~~ ** Twater,in = 6.0000
> > > ** ~~~ ** Tair,out = 18.0000
> > > ** ~~~ ** Wair,out = 8.000000E-003
> > > ** ~~~ ** The revised design conditions are: Tair,out = 14.5987
> > > ** ~~~ ** Wair,out = 9.371939E-003
> > >
> > > All my coil inputs possible are autosized. Zone and System humidity
> > designs are 0.008 (default). My outlet Tair design is 18 deg (as seen
> > in the error msg.)
> > >
> > > 1) What is going on here exactly?
> > > 2) How can I enter other parameters so that the error does not occur
> > and no reheat is nessesary.
> > >
> >
> >
>
> --
> 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
>


-- 
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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