[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [EnergyPlus_Support] Re: ZoneHVAC: Ideal Loads Air system





What I found recently in looking at the New OpenStudio software, is that the default condition is not to run the DesignDay objects.  In Sizing:Zone and system objects, the cooling temperature is also very low.   The OSM does not really make sense to me with so many connection numbers.  I could not keep track of all these numbers.  There may be some other differences.  
 
One click in DesignBuilder may request  hundreds of meter report variables, which would again generate warnings.  
 
Many user are sizing using the full annual weather file data, hence the long running time, and possible poor  results.
 
The IdealLoadsAirSystem does not have a cooling coil  to remove the moisture at each timestep, therefore it issues a warning and reset the RH value.  Some objects do report the moisture condensation state.  

 Dr. Li  

 

To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: nirajpoudel@xxxxxxxxx
Date: Fri, 3 Feb 2012 00:06:40 +0000
Subject: [EnergyPlus_Support] Re: ZoneHVAC: Ideal Loads Air system

 

Dear Dr. Li,

Thank you so much for your response.

Actually I modeled this office (50ft by 20ft) in openstudio and ran the simulation on Eplus.

I think you are right, I might have too many people in the room and that probably has driven the saturation temperature to 246 degrees.

I will start running simulations for design day as well from now on in order to debug the model. Thank you for pointing me in the right direction.

Sincerely yours'
Niraj Poudel
Clemson University

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
>
>
> If you are using third party software, I am not surprised. If you are using EPlus without the proper DesignDay object data and sizing data and schedule, you may get them also.
>
> 7799 warnings is less than one every hour in an annual simulation. You may have too many people in a zone so that the RH is more than 100% driving the saturation temperature to 246 degree. This is probaboly reset to 100% by the program and continue without severe error. The moisture in a real system is condensed out at the cooling coil. You may see a number of RH = 100% values and no warnings. I am not sure, but I do not get these warnings as soon I inserted the DesignDay sizing into the IDF's submitted by the user in the group. If you move the wet-bulb temperature up in the SummerDesignDay object, you may get simillar warnings. I do not use annual simulation in the debugging stage, and can therefore track the error more easily. Dr. Li
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> From: nirajpoudel@...
> Date: Thu, 2 Feb 2012 21:37:16 +0000
> Subject: [EnergyPlus_Support] ZoneHVAC: Ideal Loads Air system
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> Dear all,
>
>
>
> I am getting these warnings, as a matter of fact 7000+ of those warnings for my simulation. I am using the IdealLoadsAirSystem...could you please let me know what this warning means?
>
>
>
> ** Warning ** Temperature out of range [-100. to 200.] (PsyPsatFnTemp)
>
> ** ~~~ ** Routine=CalcPurchAirLoads, Environment=ATLANTA, at Simulation time=01/04 09:45 - 09:46
>
> ** ~~~ ** Input Temperature=246.36
>
> ** Warning ** Calculated Humidity Ratio invalid (PsyWFnTdbH)
>
> ** ~~~ ** Routine=CalcPurchAirLoads, Environment=ATLANTA, at Simulation time=01/25 14:15 - 14:16
>
> ** ~~~ ** Dry-Bulb= 13.00 Enthalpy= -66736.483
>
> ** ~~~ ** Calculated Humidity Ratio= -3.1602E-002 ... Humidity Ratio set to .00001
>
> ************* ===== Recurring Error Summary =====
>
> ************* The following recurring error messages occurred.
>
> *************
>
> ************* ** Warning ** Temperature out of range [-100. to 200.] (PsyPsatFnTemp)
>
> ************* ** ~~~ ** This error occurred 430 total times;
>
> ************* ** ~~~ ** during Warmup 0 times;
>
> ************* ** ~~~ ** during Sizing 0 times.
>
> ************* ** ~~~ ** Max=27499.636024 C Min=205.531742 C
>
> *************
>
> ************* ** Warning ** Calculated Humidity Ratio invalid (PsyWFnTdbH)
>
> ************* ** ~~~ ** This error occurred 7366 total times;
>
> ************* ** ~~~ ** during Warmup 0 times;
>
> ************* ** ~~~ ** during Sizing 0 times.
>
> ************* ** ~~~ ** Max=-1.029031E-004 [] Min=-2562.865899 []
>
> *************
>
> *************
>
> ************* ===== Final Error Summary =====
>
> ************* The following error categories occurred. Consider correcting or noting.
>
> ************* 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-- 7799 Warning; 0 Severe Errors; Elapsed Time=00hr 14min 58.52sec
>
>
>
> Sincerely yours'
>
> Niraj Poudel
>
> Clemson University
>




__._,_.___


Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx

The primary EnergyPlus web site is found at:
http://www.energyplus.gov

The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/

Attachments are currently allowed but be mindful that not everyone has a high speed connection.  Limit attachments to small files.

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.




Your email settings: Individual Email|Traditional
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe

__,_._,___