[Equest-users] External roofs of zones and roofs as shades

[Lars Fetzek]

Equesters,
 
    I have two questions:
 
1.    Suppose that I have a roof on the top floor of a building.  Suppose
that that roof is comprised of several sections.  (Some tile over insulated
deck here.  Some green roof there.  Etc.)  Suppose that the top floor (i.e.
directly beneath the roof) has an open ceiling (i.e. without plenum, drop
ceiling, etc.) and is comprised of several HVAC zones.  The problem is that
the borders of these various zones do not coincide with the borders of the
various roof sections.  Since the HVAC zones are assigned to spaces, must I
define the roof by the zillion or so polygons that are delineated by every
border of roof section and every border of spaces?  Alternatively, can I
ignore the geometry of the spaces beneath and simply define my roof polygons
according to the roof sections alone, since the roof is defined as an
"external wall"?  I am hoping that the latter solution is acceptable, but
will do the former if necessary.
 
2.    I have learned the benefit of jumping back-and-forth between the BDL
of the .inp file and the windows/menu interface of eQuest.  However, I
noticed something strange:  I define (via a text editor) roofs (external
walls) as they are to be built - including the overhangs.  I include the
line, "SHADING-SURFACE = YES", as the DOE2-2 dictionary explains is
allowable.  Since roof shapes can be defined by polygons while building
shades must be defined as rectangles, my approach saves a whole lot of work
relative to defining all of the many overhangs as individual rectangular
building shades.  However, once I load my .inp file into eQuest and save it,
the line, "SHADING-SURFACE = YES" is deleted (by eQuest).  Now I have no
idea whether my roof overhangs effectively shade anything from sunlight or
not.  Does anyone know?  Why does eQuest delete this line?  Do I have to add
a separate rectangular building shade at every roof overhang to acheive the
desired effect?
 
    Thank you in advance for any insight/advice on these two matters.
 
Lars Fetzek, EI
Phoenix Engineering Group
Tampa, Florida
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