Description of an exact recursive method to simplify shading calculations
An exact, recursive method called SHADE is described which attempts to simplify shading calculations as performed by a programmable calculator or microcomputer. Preliminary applications of SHADE using a Hewlett Packard HP-41C programmable calculation are outlined. In particular, for a given solar hour, SHADE is used to compute the following quantities for overhang and side fin combinations which shade various openings: the percentage of the total area of the opening which is shaded; the shaded area itself; the cosine of the angle of incidence between sun and glazing surface; the direct insolation at this surface, with and without shading; and the direct solar power at this surface, with and without shading. Hence, in its present HP-41C application, SHADE can be used in preliminary design and comparative analyses of shading devices on an hourly, daily, or seasonal basis, provided that: (1) the fins and overhangs be square or rectangular, and lie in planes perpendicular to the plane of the opening; and (2) the opening itself be vertical and rectangular with arbitrary building azimuths. Design candidates include conventional overhangs and side fins, porches, and reveals. In principle, SHADE can be extended to awnings, slatted sun screens, and bevelled recesses; in addition, its HP-41C application can be extended to calculations of direct solar gain through vertical and non-vertical glazings, thereby providing a more useful tool in building heating and cooling load calculations.
- Research Organization:
- Lawrence Berkeley Lab., CA (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6207128
- Report Number(s):
- LBL-11390; CONF-810405-16; ON: DE81027409
- Resource Relation:
- Conference: 3. annual systems simulation, economic analysis/solar heating and cooling operational results conference, Reno, NV, USA, 27 Apr 1981
- Country of Publication:
- United States
- Language:
- English
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