DOE-2 Reference Manual Version 2.1 - DOE2.com

5. BUILDING-SHADEThe BUILDING-SHADE instruction is used to specify the opacity, position,size, and orientation of external surfaces that shade exterior surfacesof the building. Some typical surfaces that cast shadows on the exteriorof a building are: a nearby building, tree, or hill, or an attachedobject, such as an overhang. It is also possible for a building to shadeitself. The program will not calculate this type of shading unless thesurface that causes theshadow is also speci fied under a BUILDING-SHADEcommand. That is, a wall may have to be specified twice; once as aBUILDING-SHADE, and once as an EXTERIOR-WALL. So that the shading surfacedoes not shade the surface it represents, it should be placed slightly(about 0.01 ft) inside of the surface located in the related EXTERIOR-WALLor ROOF instruction. If the space and building coordinate systems areidentical, the HEIGHT, WIDTH, AZIMUTH, and TILT keyword values inBUILDING-SHADE will be identical to the respective keywords in the relatedEXTERIOR-WALL or ROOF instruction.Only the direct component of solar radiation is affected by BUILDING­SHADE. Diffuse solar radiation from the sky and ground is not affectedby BUILDING-SHADE. To account for the shading of diffuse radiation,values for SKY-FORM-FACTOR and GND-FORM-FACTOR should be specified forthe affected EXTERIOR-WALLs and WINDOWs (see EXTERIOR-WALL and WINDOWinstructions).Further description of the locating of building shades is in Sec. A ofthis chapter.U-nameBUILDING-SHADEHE IGHTWIDTHTRANSMITTANCEXYZAZIMUTHmay be entered in the name field, but is not required.This command tells LOADS that the data to follow specify ashading surface.of a shading surface is expressed in feet.of a shading surface is expressed in feet.is a decimal fraction expressing the ratio of the directsolar radiation that passes through a shading surface to thetotal insolation. The default value is 0.0, which means thesurface is opaque. If the surface is transparent, the valueto enter would be 1.0. Other values may be specifed as adecimal fraction between these 1 imits. The diffuse componentof the solar radiation is not affected by this entry.are the coordinates of the lower left corner of the surface,as viewed from the opposite direction of the surface outwardnormal. These coordinates are in the building coordinatesystem and have units of feet.is the angle (in degrees) between the Y-axis of the buildingcoordinate system and the projection of the shading surfaceoutward normal onto the X-V plane of the buil ding coordinateI II. 35 (Revised 5/81)