     This document serves as    tions  about the window sys-
a brief introduction to WIN-    tem (Figure 1).  The program
DOW 3.0, which is a  general    is  being modified to handle
purpose  thermal  model of a    inclined   glazing   (heated
window  system.   Like   its    surface down).
predecessor,   WINDOW   2.0,
this   program    calculates    Glazing Properties:
solar   optical  properties,
heat   fluxes,   temperature         The next screens  allow
gradients,    U-values   and    the  user  to define glazing
shading        coefficients.    layers (Figure 2).  For each
Several  modifications  have    glazing  layer  (layers num-
been  made  to   the   heat-    bered from the outside  in),
transfer  model  that do not    the user must choose a glaz-
outwardly affect the appear-    ing layer  number  from  the
ance  of  the  program.   In    glazing  library.  The glaz-
addition, WINDOW 3.0  has  a    ing   library   is    easily
new   format  that  is  com-    accessed  with  the  F1  key
pletely   interactive    and    (Figure  3).    Inside   the
highly flexible (see Figures    glazing library appear glaz-
at end of text).   Libraries    ing library numbers,  names,
of  glazing/coating and gas-    and     properties    (solar
fill   properties   can   be    transmittance  and   reflec-
accessed  and  extended from    tances,   visible  transmit-
within the program.  After a    tance   and    reflectances,
test   period   of  about  2    infrared  transmittance  and
months, WINDOW  3.1,  incor-    emissivities).  The user may
porating   the  comments  of    choose to look at the entire
industry reviewers, will  be    library,   to   search   for
released to the full mailing    entries  by  the first three
list.                           characters of  their  names,
                                to  search for glazings with
Running the Program:            a given thickness (_10%), to
                                search for glazings with one
     As  with  WINDOW   2.0,    surface's emissivity under a
WINDOW  3.0  is  expected to    certain value, to define new
run on all IBM  PC  compati-    glazing layers, or  to  exit
bles.  If a color monitor is    from the library back to the
available, the program  will    glazing layer screen.  Glaz-
make  use  of  this feature.    ing  layers  can  be deleted
To start the  program,  type    from the library by deleting
WINDOW3.                        the  appropriate information
                                from the  glass.dat  on  the
Window Configuration:           WINDOW  3.0  disk.   Once  a
                                glazing  number   has   been
     The input to WINDOW 3.0    chosen, the layer's name and
is   divided  into  separate    above properties will appear
screens  with  each   screen    schematically on the screen.
focusing  on  a component of    The user now has the  option
the window system.  To start    of changing any one of these
the  program,  type  WINDOW3    properties by  skipping  the
and then press  the  "enter"    cursor through each block on
key.   The first screen con-    the screen  with  the  enter
tains  several  basic  ques-    key  and  making  changes as
