Re: [EnergyPlus_Support] Initial conditions

["Michael J. Witte" <mjwitte@xxxxxxxx>]

There is no direct user control over initial conditions.  Here is a summary of 
the initializations which are performed at the beginning of each environment 
(an environment is  RunPeriod or a DesignDay):

1.  All building heat transfer related temperatures are initialized to 23C.

2.  All HVAC system nodes are initialized to 20C and the outdoor humidity ratio 
of the first time step of weather data.

3.  The first day of the environment is repeated until the changes in zone 
loads and zone and surface temperatures are less than the tolerances specified 
in the BUILDING object.  If convergence is not reached within the "Maximum 
Number of Warmup Days" (which defaults to 25 days, see the BUILDING object), 
then a warning is issued "Loads Initialization did not Converge".

The only way for the user to control intialization would be to customize a 
weather data file with an initial time period long enough to establish the 
desired initial conditions and then have the weather data proceed into the 
period of interest.

Mike


On 1 Jun 2006 at 16:40, aboyemeplus wrote:

> What are the initial conditions assumed in each EPlus simulation? Can 
> some or all initial conditions be defined by the user to simulate, for 
> example, recovery from a temporary loss of HVAC equipment? 
> My search for information on the subject, in both the user 
> documentation and support database, was not successful. Can anyone 
> help?   
> 
> Thank you for the support.
> 
> Merid 
> 
> 
> 
> 
> 
> 
> 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 not allowed -- please post any files to the appropriate folder
> in the Files area of the Support Web Site.
> 
> EnergyPlus Documentation is searchable.  Open EPlusMainMenu.idf and press the
> "search" button.
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
> 
> 


========================================================
Michael J. Witte, GARD Analytics, Inc.
EnergyPlus Testing and Support      
EnergyPlus-Support@xxxxxxxx





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