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Re: [EnergyPlus_Support] Warning Calculated Humidity Ratio
Hello,
Actually the dry bulb is above the wet bulb,
Dry-Bulb= -24.40 Wet-Bulb= -25.40
-25.4C is less than -24.4C or about 1 degree lower. The problem is that
the wet bulb is too low and then the calculated RH is slightly
negative. The RH routine then resets RH to slightly above 0, a physical
possibility.
Thanks Richard Liesen
At 09:38 AM 4/10/2003, you wrote:
>The message shows that the Dry-Bulb temperature is
>below the Wet-Bulb temperature, an impossible
>condition. The weather routine should check for this
>condition and set the wet-bulb temperature equal to
>the dry-bulb temperature whenever wet-bulb temperature
>is calculated to be above the dry-bulb temperature.
>
>--- "Richard J. Liesen" <rliesen@xxxxxxxx> wrote:
> > Hello Alex,
> >
> > What this message is telling you is that the
> > calculated humidity ratio is
> > below the physical realm of possibility, a very
> > small negative value, and
> > it is setting it to a very small physical value.
> > Either the dry and wet
> > bulb, or the numerical procedures are slightly off
> > at this physical
> > boundary, but either way the warning generated is
> > within numerical
> > precision and I doubt that this will cause any
> > distortion of results. The
> > reason that it should not cause any distortion is
> > that you are probably in
> > heating scenarios and this is normally all sensible
> > heat transfer.
> >
> >
> > Thanks Richard Liesen
> >
> >
> > At 05:14 PM 4/10/2003, Alexander Beisteiner wrote:
> > >Dear E+ User,
> > >
> > >A weather file simulation of a purchased air system
> > produces the
> > >following warning message:
> > >
> > >Program Version,EnergyPlus 1.0.3.019, 10.04.2003
> > 15:52
> > > ************* Testing Individual Branch
> > Integrity
> > > ************* All Branches passed integrity
> > testing
> > > ************* No node connection errors were
> > found.
> > > ** Warning ** Calculated Humidity Ratio Invalid
> > (PSYWTP)
> > > ** ~~~ ** (mm/dd/hh)= 1/05/01 Dry-Bulb=
> > -24.40 Wet-Bulb= -25.40
> > >Pressure= 97500.00
> > > ** ~~~ ** Calculated Humidity Ratio=
> > -2.3594E-006 ... Humidity
> > >Ratio set for a relative humidity ratio of .01
> > > ** Warning ** Calculated Humidity Ratio Invalid
> > (PSYWTP)
> > > ** ~~~ ** (mm/dd/hh)= 1/05/01 Dry-Bulb=
> > -25.30 Wet-Bulb= -26.30
> > >Pressure= 97700.00
> > > ** ~~~ ** Calculated Humidity Ratio=
> > -3.6357E-005 ... Humidity
> > >Ratio set for a relative humidity ratio of .01
> > > ** Warning ** Calculated Humidity Ratio Invalid
> > (PSYWTP)
> > > ** ~~~ ** (mm/dd/hh)= 1/05/01 Dry-Bulb=
> > -26.10 Wet-Bulb= -27.10
> > >Pressure= 97800.00
> > > ** ~~~ ** Calculated Humidity Ratio=
> > -6.3930E-005 ... Humidity
> > >Ratio set for a relative humidity ratio of .01
> > > ** Warning ** Calculated Humidity Ratio Invalid
> > (PSYWTP)
> > > ** ~~~ ** (mm/dd/hh)= 1/05/01 Dry-Bulb=
> > -27.00 Wet-Bulb= -28.00
> > >Pressure= 97900.00
> > > ** ~~~ ** Calculated Humidity Ratio=
> > -9.2471E-005 ... Humidity
> > >Ratio set for a relative humidity ratio of .01
> > > ** Warning ** Calculated Humidity Ratio Invalid
> > (PSYWTP)
> > > ** ~~~ ** (mm/dd/hh)= 1/05/01 Dry-Bulb=
> > -27.30 Wet-Bulb= -28.30
> > >Pressure= 98000.00
> > > ** ~~~ ** Calculated Humidity Ratio=
> > -1.0164E-004 ... Humidity
> > >Ratio set for a relative humidity ratio of .01
> > > ** Warning ** Calculated Humidity Ratio Invalid
> > (PSYWTP)
> > > ** ~~~ ** (mm/dd/hh)= 1/05/01 Dry-Bulb=
> > -27.60 Wet-Bulb= -28.60
> > >Pressure= 98100.00
> > > ** ~~~ ** Calculated Humidity Ratio=
> > -1.1054E-004 ... Humidity
> > >Ratio set for a relative humidity ratio of .01
> > > ************* Psychrometric Error Summary
> > > ************* Routine - Number of errors
> > > ************* PSYDPT-0
> > > ************* PSYRHT-0
> > > ************* PSYTWD-0
> > > ************* PSYVTW-0
> > > ************* PSYWDP-0
> > > ************* PSYWTH-0
> > > ************* PSYWTP-363
> > > ************* PSYWTR-0
> > > ************* SATUPT-0
> > > ************* SATUTH-0
> > > ************* SATUTP-0
> > > ************* tp12c0-0
> > > ************* tp12c1-0
> > > ************* tp12h0-0
> > > ************* tp12h1-0
> > > ************* freeze-0
> > > ************* EnergyPlus Completed
> > Successfully-- 6 Warning; 0 Severe
> > >Errors; Elapsed Time=00hr 00min 13sec
> > >
> > >Looking at the weather file (of Irkutsk), I could
> > not find temperature
> > >and pressure values for the time stated: 1/05/01.
> > What does the warning
> > >tell? Does it distort results? Can the message be
> > neglected?
> > >
> > >I am looking forward to your help.
> > >
> > >Alexander
> > >
> > >_______________________________________
> > >DI (FH) Alexander Beisteiner
> > >Wissenschaftlicher Mitarbeiter
> > >
> > >Forschungs- und Technologietransfer Pinkafeld GmbH
> > >Steinamangerstraße 21
> > >A - 7423 Pinkafeld
> > >Tel.: +43-3357-45370 DW 1324
> > >Fax.: +433357-45370 DW 1010
> > >
> > >
> > >
> > >
> > >
> > >[Non-text portions of this message have been
> > removed]
> > >
> > >
> > >
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