Re: [EnergyPlus_Support] Window Calculation

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

One additional comment regarding film (convection) coefficients.  
During the simulation, all interior and exterior film coefficients 
are changing as the direction of heat flow, temperature difference, 
and wind speed change.  The nominal value used when reporting the 
overall window U value in the walls report in the eio file is not the 
value used for the entire simulation.  

Mike


On 29 Apr 2003, at 11:14, Linda Lawrie wrote:

> Some email has gone on behind the scenes, but the answers are included
> below:
> 
> At 02:32 AM 4/29/2003, Alexander Beisteiner wrote:
> >1)       In the case of windows, the external film coefficient cannot
> >be set with the object "ConvectionCoefficients". This means, if a
> >value is defined, the output variable for the window external
> >convection coefficient is zero. Is this deliberate?
> 
> This was a bug in the program.  It is not (1.1.0.018) doing the user
> supplied convection coefficients (an advanced feature) correctly.  We
> hope to issue an update for this and several other problems that were
> late-breaking soon.
> 
> >2)       As defined on page 41 in the Output Details and Examples-
> >manual, the calculated conductance does not include film
> >coefficients. Comparing this result to the Window5 calculation,
> >values are the same, but the Window5 calculation includes film
> >coefficients. Might it be possible, that the E+ output for the
> >U-Value includes the film coefficient? In that case, can the window
> >U-Value be assumed to be constant, independent of the variable
> >external convection coefficient?
> >
> 
> The documentation was incorrect -- windows are reported WITH film
> coefficients.  However, there is a change request (CR) to have both
> Window Constructions and other Constructions reported with and without
> film coefficients in this report.  (As noted above, the other
> Constructions are already reported WITHOUT film coefficients). 
> However, note that user supplied convection coefficients add a new
> degree of complexity here -- therefore, the nominal film coefficient
> reporting will be for standard conditions -- and will be documented
> thereof.
> 
> 
> Linda
> 
> EnergyPlus WebSite: http://www.energyplus.gov
> Owner: EnergyPlus_Support list
> Member: EnergyPlus Development Team
> 
> 
> 
> ------------------------ Yahoo! Groups Sponsor
> ---------------------~--> Get 128 Bit SSL Encryption!
> http://us.click.yahoo.com/xaxhjB/hdqFAA/bW3JAA/dkFolB/TM
> ---------------------------------------------------------------------~
> ->
> 
> To unsubscribe from this group, send an email to:
> EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx
> 
> 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 are of the Support Web Site.
> 
> 
> 
> 
> 
> 
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/ 
> 



========================================================
EnergyPlus Testing and Support      
EnergyPlus-Support@xxxxxxxx


------------------------ Yahoo! Groups Sponsor ---------------------~-->
Get A Free Psychic Reading! Your Online Answer To Life's Important Questions.
http://us.click.yahoo.com/O10svD/Me7FAA/uetFAA/dkFolB/TM
---------------------------------------------------------------------~->

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

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 are of the Support Web Site.




 

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