Re: [EnergyPlus_Support] VAV Boxes

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

After some digging, we have verified that there is a problem with the behavior 
of the reheat controls in version 1.3.0 under certain conditions.  Without 
getting into too much detail, if the zone thermostat predicts that the zone 
would be in the deadband (between the heating and cooling setpoint) with no 
HVAC operation, it sets a "deadband" flag.  When the deadband flag is active, 
the reheat coil will not operate.  If the min flow of cold air from the VAV 
terminal unit cools the zone below the heating setpoint, the reheat coil will 
not come on until the next time step.  The solution is oscillating between 
these states.  I do not know of a workaround to get this to behave any better 
in 1.3.0.018.

Mike


On 15 Jun 2006 at 11:33, Peter G Loutzenhiser wrote:

> 
> >Hello All,
> 
> 
> I have just started using the 1.3 version of 
> EnergyPlus with a VAV reheat system and a dual 
> heating/cooling setpoint temperature.  I have 
> 13.6°C air entering the coil and I have a heating 
> setpoint of 22°C.  I have given the reheat coils 
> plenty of capacity and yet I still get zone 
> temperature below the heating setpoint (in the range of 21.7°C).  Why is
> this?
> 
> Peter
> 
> 
> 
> 
> 
> 
> 
> 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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