Re: [EnergyPlus_Support] Errors of autosizing the fan coil unit and the air-to-air heat pump at one time

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

EnergyPlus autosizing is not able to split the load between multiple units 
serving the same zone.  It will attempt to size both units to meet the entire 
heating and cooling load.  

The zone equipment list controls the sequence in which multiple units are 
simulated to meet the current zone load.  

As a starting point, you should be able to autosize both units to meet the full 
load.  Then you can decide what portion of the loads should be met by each unit 
and then specify hard sizes for everything based upon the sizing outputs in the 
eio file.

If the design load for the heating coil is zero, then there is something wrong 
in one of the sizing objects.  Check the thermostat, zone sizing, system 
sizing, and plant sizing inputs.

Mike


On 1 Jul 2006 at 6:37, energypluser wrote:

> Dear all
> 
> I set up a fan coil unit to serve one room accompied by a direct air object
> which is served by 
> an air-to-air heat pump. 
> Since I lack of the performance data of both units, I chose to autosize these
> two object at one 
> time. I set the fan coil has the highest priority for air conditioning, and
> the direct air is an 
> assistant.
> The node-branch connection passed the test.
> However, the design load for heating coil became 0, and the leaving humidity
> of the cooling 
> coil is bigger than the entering humidity.
> For the heat pump, the air volume flow rate per watt of rated total heating
> capacity is out of 
> range.
> How, can I fix them?
> should I set up the parameters for the fan coil unit, and then autosize the
> heat pump alone?
> And I wonder whether the configuration of the zone equipment list can set the
> priorities of 
> the equipments?
> Thank you in advacne
> 
> mac.cz 
> 
> 
> 
> 
> 
> 
> 
> 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





------------------------ Yahoo! Groups Sponsor --------------------~--> 
See what's inside the new Yahoo! Groups email.
http://us.click.yahoo.com/2pRQfA/bOaOAA/yQLSAA/dkFolB/TM
--------------------------------------------------------------------~-> 

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

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/

<*> To unsubscribe from this group, send an email to:
    EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/