In your idealHVAC system you enter a supply air temperature (and usually also a humidy ratio). At the minute, your outdoor air appears to be heated up to 13C but is almost completely dry. The routine has calculated a negative value which it interperets as having passed the applicable limits of the formula, so it then sets the humidity to be as dry as possible.
If you started with -20C outdoor air, for example, you may find that the air is indeed completely dry at 13C. I don't have a phychometric chart in front of me so I can't tell you, but I suggest you check one to make sure this is correct.
Perhaps you have an input error somewhere. Perhaps this is all correct and the software is behaving correctly. It is a warning, not an error. It prompts you to double check.
Mit freundlichen Grü�en- Sent from my iPhone (excuse the brevity)
i. A.
Jean Marais
b.i.g. bechtold
Tel. +49 30 6706662-23
On 30.12.2014, at 09:36, "Zahra Balador zbalador@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
hiI have this problem while I want to analyze cooling heating energy and mean temperature, although I have not fill any field of humidity...Program Version,EnergyPlus-32 7.0.0.036, 2014/12/23 02:01 ب.ظ,IDD_Version 7.0.0.036
************* Testing Individual Branch Integrity
************* All Branches passed integrity testing
************* Testing Individual Supply Air Path Integrity
************* All Supply Air Paths passed integrity testing
************* Testing Individual Return Air Path Integrity
************* All Return Air Paths passed integrity testing
************* No node connection errors were found.
************* Beginning Simulation
** Warning ** Calculated Humidity Ratio invalid (PsyWFnTdbH)
** ~~~ ** Routine=CalcPurchAirLoads, Environment=RUN1, at Simulation time=06/05 23:00 - 23:10
** ~~~ ** Dry-Bulb= 13.00 Enthalpy= 12752.029
** ~~~ ** Calculated Humidity Ratio= -1.2311E-004 ... Humidity Ratio set to .00001
************* Simulation Error Summary *************
************* There are 1 unused schedules in input.
************* Use Output:Diagnostics,DisplayUnusedSchedules; to see them.
*************
************* ===== Recurring Error Summary =====
************* The following recurring error messages occurred.
*************
************* ** Warning ** Calculated Humidity Ratio invalid (PsyWFnTdbH)
************* ** ~~~ ** This error occurred 242 total times;
************* ** ~~~ ** during Warmup 0 times;
************* ** ~~~ ** during Sizing 0 times.
************* ** ~~~ ** Max=-1.030496E-004 [] Min=-8.683894E-004 []
*************
************* EnergyPlus Warmup Error Summary. During Warmup: 0 Warning; 0 Severe Errors.
************* EnergyPlus Sizing Error Summary. During Sizing: 0 Warning; 0 Severe Errors.
************* EnergyPlus Completed Successfully-- 242 Warning; 0 Severe Errors; Elapsed Time=00hr 02min 16.03sec
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Posted by: "jeannieboef@xxxxxxxxx" <jeannieboef@xxxxxxxxx>
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