[Equest-users] Interior Wall Conduction and why it screws up building heat loads

[James Hansen]

Thanks for everyone's help on the custom weather file info the other
week.  Modifying the CSV value using the energy plus weather editor is
definitely the way to go.

 

I have a question about what exactly "interior wall conduction" is.  

 

This item shows up in the peak building load calculations under the LS-C
report, and for my project, which is a strange industrial building that
only needs to maintain 40 degrees, it accounts for 345 KW on the peak
day.  At first I thought it might have something to do with interior
walls and floors storing energy.  However, it turns out that when I
create an hourly report to list this value for ALL hours, it is almost
constant throughout the entire year.  In fact, it simply bounces back
and forth between 345 KW and 360 KW for the whole year, with no pattern
to the madness.  This makes no sense to me.  It is technically listed in
the hourly report as:

 

"Building heat load from int wall conduction"

 

How can there be a 345 KW interior wall conduction heat load when its 90
degrees outside and I'm only trying to maintain 40 degrees (no cooling
system in the building)? 

 

Is this a bizarre custom weighting thing, or what?  All of my interior
walls are set up as "AIR" walls since there are really no walls
throughout the 12-story complex.

 

Also, there is absolutely NO lighting and NO equipment listed.  The only
heat in/out from the building is as I've defined for wall conduction,
windows, and infiltration.

 

Any advice would be appreciated!  I feel like this might be screwing
with the unit ventilator air system calculations.  In addition, I'm
starting to think that this might be why a lot of my projects end up
having heating loads when I don't think they should....

 

OH - and one last thing.  Just because the peak cooling load below
doesn't show any cooling load from internal surface conduction doesn't
mean the heating component isn't still showing up for every hour of the
year.

 

 

 

GHT Limited
James Hansen, PE, LEED AP

Senior Associate

1010 N. Glebe Rd, Suite 200

Arlington, VA  22201-4749

703-338-5754 (Cell)

703-243-1200 (Office)

703-276-1376 (Fax)

www.ghtltd.com <http://www.ghtltd.com/> 

 

 

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