DOE-2 Reference Manual Version 2.1 - DOE2.com

. Space Coordinate SystemThe location of a space and its associated space coordinate systemare defined relative to the building coordinate system by the keywordsX, Y, Z, and AZIMUTH in the SPACE instruction (see Figs. II1.3 and111.4). The location of the origin of the space coordinate system isspecified by assigning values to X, Y, and Z. The orientation of thespace coordinate system is such that its z-axis is vertical and x-yplane is horizontal (right-hand cartesian coordinate system). Thespace and its coordinate system may be rotated about the z-axis bygiving a value to the keyword AZIMUTH. The AZiMUTH is defined as theclockwise angle between the building y-axis and the space y-axis. Ifthe user does not specify X, Y, Z, and AZIMUTH, the keyword valuewill default to zero and the space coordinate system becomes identicalwith the building coordinate system.c. Surface Coordinate SystemA surface and its surface coordinate system are located relative tothe space coordinate system by the keywords X, Y, Z, AZIMUTH, andTILT in the EXTERIOR-WALL or ROOF instruction. Windows are locatedrelative to the surface coordinate system. The location of the originof the surface coordinate system relative to the origin of the spacecoordinate system is specified by assigning values to X, Y, and Z.The origin of the surface coordinate system is the lower left-handcorner of the wall, as seen by an observer viewing the surface in thedirection opposite to the surface outward normal. The orientation ofthe coordinate system is fixed by the keywords AZIMUTH and TILT. TheAZIMUTH is the clockwise angle between the space coordinate systemy-axis and the horizontal projection of the outward normal of thewall or roof associated with the surface coordinate system (see Fig.II 1.5). To specify az imuth for a hor i zon ta 1 surface, see thediscussion of Fig. 111.9.The surface coordinate system should be regarded as embedded in itsassociated exterior wall or roof. The x-axis runs along the width ofthe wall, the y-axis points along the height of the wall, and thez-axis is parallel to the surface outward normal. The TILT is thenthe a~gle between the vertical and the surface outward normal, andthe AZIMUTH is the clockwise angle between the space coordinate systemy-axis and the projection of the surface outward normal on the horizontalplane.5. Use of the Coordinate Systemsa. quick Method for Locating Walls, Ceilings, and Floors (in Box-shapedSPACEs)For box-shaped SPACEs (rectangular parallelepipeds) only, there is aneasy method of locating and orienting its walls. The user inputsSHAPE = BOX and assigns values to HEIGHT, WIDTH, and DEPTH in theSPACE instruction. For the walls, he may then simply assignII 1.10 (Revised 5/81)