Re: [EnergyPlus_Support] Main Branch Cooling Coil and Heating Coil Control Nodes

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

EnergyPlus controllers all have a finite control tolerance (specified in the 
controller object), so the control is not perfect.  My guess is that the 
heating and cooling coil controllers are battling each other.  

If I understand your application correctly, SET POINT MANAGER:SINGLE ZONE 
HEATING and SET POINT MANAGER:SINGLE ZONE COOLING can be used to control your 
system.  

Move the heating coil to be after the fan and place the SET POINT 
MANAGER:SINGLE ZONE HEATING setpoint on the heating coil outlet node.  

Place the SET POINT MANAGER:SINGLE ZONE COOLING setpoint on the fan outlet node 
and use a SET POINT MANAGER:MIXED AIR to place a setopint minus fan heat 
correction on the cooling coil outlet node.

Mike


On 27 Feb 2006 at 15:55, Elmer Morrissey wrote:

> Hello all,
> 
> I am getting max iterations on a loop  and I'm trying to go through 
> the file iteratively to locate the source of the problem (node 
> connections, correct flowrates etc). 
> 
> A brief description of the system I am trying to emulate:
> 
> I have a fixed flow system. The AHU takes full fresh air before 
> entering a cooling coil, a heating coil and a supply fan (no 
> reheat). The temperature leaving the supply fan is varied according 
> to zone temperature.
> 
> What I have done:
> 
> I have two Controller:simple objects which both use the same control 
> node (the supply fan outlet node). I have set this at 18oC. However, 
> I would prefer to let EnergyPlus decide what the setpoint should be.
> 
> Could this be the source of my problems?
> 
> Kind regards
> 
> -Elmer
> 
> 
> 
> 
> 
> 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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