DOE-2 Reference Manual Version 2.1 - DOE2.com

13. GLASS-TYPEThis instruction is used to specify the type of glass used in a window.U-nameGLASS-TYPELIKEis a mandatory entry for this command.tells LOADS that the data to follow specify thecharacteristics of the glass used in a window.may be used to copy data from a previously U-namedGLASS-TYPE instruction.PANES Number of panes of glass; the code numbers arerespectively 1, 2, or 3 for single-, double-, ortriple-pane.GLASS-TYPE-CODEis a code-number that identifies the type of glass used inthe window. Two methods are available for calculatingsolar heat gain through windows. If GLASS-TYPE-CODE isspecified, the program will use precalculated transmissionand absorption coeffi cients to determine sol ar gainas a function of angle of incidence of solar radiation.Alternatively, if SHADING-COEF is entered, the ASHRAEshading coefficient technique will be used to calculatesolar gain (see below).To use GLASS-TYPE-CODE, refer to Table II I. 1. This tablegives the overall transmittance and reflectance for solarradiation at normal incidence for different values ofGLASS-TYPE-CODE and number of panes. For example, ifGLASS-TYPE-CODE ; 6 and PANES; 1, the normal transmittanceis 50 per cent and the reflectance is 6 per cent. (Thecorresponding absorptance is 100 - 56 ; 44 per cent; ofthe radiation absorbed, part is conducted into the space,and the rest is conducted back out of the window.) Notethat the transmittance given in Table III. 1 is for theentire solar spectrum, not just the visible portion.Also shown in Table IlL1 is the default value of theconductance of the window, excluding outside air film (seeGLASS-CONDUCTANCE keyword below), and the overall U-value,including outside air film, for?5 and 15 mph wind speed.GLASS-TYPE-CODEs 1 through 8 are for uncoated gl ass,whereas values of 9, 10, and 11 correspond to clear,1/4"-thick panes with a reflective coating (solar-controlfilm) on the inside of the outer pane. This film acts toreflect a large fraction of the incident radiation. (Atthe present time, there is no GLASS-TYPE-CODE forrefl ective coati ngs on heat-absorbing gl ass; in th is case,SHADING-COEF should be used).II I.8? (Revised 5/81)