[EnergyPlus_Support] Exhaust Fan Operation and Connections

["asheaffe" <sheaffer@xxxxxxx>]

To All,

Ah yes, another problem from the troublemakers here at UIC.  
Sometimes I wonder if Gard has ever considered revoking our EPlus 
license - I hope there isn't a user idiocy clause in the agreement.  
Anyhow, I am having trouble setting up exhaust fans.  The short 
version of the problems is that I cannot get several exhaust fans to 
operate and pass zone exhaust to the appropriate connected nodes.  
The file that I am having trouble with is posted as (C2+_19.idf).  
The problematic exhaust fans are all of the exhaust fans in the 
file.  The eso states that there is no flow through the fan input 
nodes and no power consumption by the fans - although the input 
nodes do correctly report zone temperatures.  The output nodes do 
show flow, but do not show the correct temperatures.  Any ideas on 
how to fix this?

The long version of the problem is that I am trying to model a DOAS 
system for packaged rooftops where I have one packaged rooftop 
pretreating ventilation air and delivering that air to the OA intake 
of the zone packaged rooftops.  The only way that I have been able 
to think of to make this work is to create associated dummy zones 
(denoted in the idf as zone names that start with a V) for each real 
zone so that I can split the flow from the pretreating rooftop using 
a zone splitter.  To ensure continuity in the Air Primary Loop, the 
return flows from the dummy zones are mixed and sent back to the 
pretreating rooftop but not recirculated (the pretreating rooftop is 
100% OA).  I supply the pretreated air from each dummy zone through 
the zone exhaust to the OA intake of the associated real zone 
packaged unit.  However, as mentioned, the flow and temperature 
conditions at the exhaust fan inlet and outlet for each fan do not 
match.  Can this be fixed?  Is there any other way that I can model 
this system - on rooftop supplying the OA intake of several others?

I have tried to set up the system without the exhaust fans (a real 
system of this type wouldn't have them - as such I have set their 
efficiencies impossibly high and their delta pressures impossibly 
low to minimize their power consuption), but then I don't have two 
independent nodes to ensure that the temperature and flow supplied 
to the zone rooftops is consistent.





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

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

<*> Your email settings:
    Individual Email | Traditional

<*> To change settings online go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/join
    (Yahoo! ID required)

<*> To change settings via email:
    mailto:EnergyPlus_Support-digest@xxxxxxxxxxxxxxx 
    mailto:EnergyPlus_Support-fullfeatured@xxxxxxxxxxxxxxx

<*> 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/