Re: [EnergyPlus_Support] Ventilation:Mechanical air flow rate do not match up

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

The problem here is because the fan, branch and air primary loop all have a max 
flow rate of 0.24861, but the zone terminal unit is only 0.1667.  If you set 
these flow rates to match, you will get the desired OA flow rate.  I will have 
to ask the OA controller expert if there is good reason for this behavior or if 
it should be changed.  In general, it is important that all parts of an air 
loop be sized consistently, whether auotsized or not.

Mike


On 3 Jul 2007 at 13:16, tobiasmaile wrote:

> Hi,
> 
> We encountered the following problem:
> The ventilation flow rates based on occupancy with the
> Ventilation:Mechanical object in a simple air loop model (see uploaded
> SimpleAirLoopVentMechProb.idf file) do not match up. The air flow rate
> is less (0.055885 m3/s) than expected (0.08335 m3/s = 0.01667 * 5)
> based on the "Ventilation rate per occupant" in the
> ventilation:mechanical object (and the number of occupants based on
> the people and schedule input). We have tried several different
> settings in the CONTROLLER:OUTSIDE AIR and removed the SIZING objects
> from the file without any change.
> 
> From what we can say it is exactly the same outside air system
> configuration than the example file HeatPumpSimpleDCV.idf.
> 
> Furthermore, is there a way to force 100% outside air into the air
> loop system. So, we want to force the air flow rate in the air loop to
> the outside air inflow that was determined by the ventilation
> mechanical object.
> 
> Thanks for your help.
> 
> Tobias & Sebastian
> 
> 
> 
> 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.pdf under the
> Documentation link 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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