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[EnergyPlus_Support] Re: Help with override error



Hi, back again. Reported the coil air temperatures and humidities entering and leaving, and they seem to be in order. Still don't see where the zone relative humidities drop to fractions.

The current problem submittal has following outputs (if you can think of any other interesting ones, pls let me know:

Output:Variable, *,Plant Loop Cooling Demand,hourly;!HVAC,Average, [W]
Output:Variable,*, Zone Mean Air Temperature, hourly, On;
Output:Variable, *, Zone Air Relative Humidity, hourly, On;


Output:Variable,DOAS Mixed Air Outlet,System Node Temp,hourly;!HVAC,Average, [C]
Output:Variable,DOAS Cooling Coil Air Outlet,System Node Temp,hourly;!HVAC,Average, [C]
Output:Variable,DOAS Mixed Air Outlet,System Node Humidity Ratio,hourly;!HVAC,Average, [C]
Output:Variable,DOAS Cooling Coil Air Outlet,System Node Humidity Ratio,hourly;!HVAC,Average, [C]
Output:Variable,DOAS Mixed Air Outlet,System Node Relative Humidity,hourly;!HVAC,Average, [C]
Output:Variable,DOAS Cooling Coil Air Outlet,System Node Relative Humidity,hourly;!HVAC,Average, [C]

!  OutputControl:Table:Style,
!    comma;                    !- Column Separator
!  Output:Table:SummaryReports,
!    AllSummary;              !- Report 1 Name

!Output:Surfaces:Drawing, DXF, Triangulate3DFace;

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Jean marais" <jeannieboef@...> wrote:
>
> Understood. I'll take a sharper look and get back to the thread later.
> 
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad <RRaustad@> wrote:
> >
> > 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 
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>, 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>
> > > > > <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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