MIL-HDBK-1003/19
4.3.9 Schematic design worksheet. Worksheet 1 is provided as an aid in
organizing and recording the results of the schematic design process
described in this chapter. The worksheet is self-explanatory and employs
previously defined notation except for the total external perimeter of the
heated floorspace (Pt). The floorspace may occupy one or more levels in a
building, and Pt comprises the external perimeter of all levels to be
included in the analysis. Thus, for a two-story building that is being
analyzed as a single unit, Pt is the perimeter of the ground floor plus
the perimeter of the upper floor. If the two-story unit is a duplex
consisting of two distinct thermal zones separated by a vertical plane, it
would be appropriate to analyze the thermal zones separately. In this case,
the length of the common wall separating the two zones must be subtracted
from the perimeter of each level of the zone under consideration.
Additional worksheets will be presented later as more detailed design
analysis procedures are introduced. Having once read and understood these
design procedures, the user will be able to rapidly specify appropriate
starting-point values for the primary passive solar parameters. The user
may then proceed to completion of a detailed method for design analysis and
refinement using only the worksheets and graphical or tabular information
provided in this document. An example calculation presented in 5.3
illustrates the entire process.
4.4 Fundamentals of design analysis. The guidelines presented in 4.3
should enable the designer to specify initial values for the design
variables that are most strongly related to energy efficient performance in
passive solar buildings. Before proceeding any further with the design, an
analysis that provides an estimate of the buildings performance should be
conducted. By repeating the analysis with selected values of the primary
variables it is possible to fine tune the original design in a manner that
is consistent with the performance and economic goals of the project. The
design analysis procedure introduced herein is quick and accurate in
application and therefore well suited to the design of energy efficient
buildings. Before discussing the procedure, a set of essential concepts and
definitions is presented below.
4.4.1
Terminology.
4.4.1.1 Solar collection area. The area of the glazed portions of the
solar collection aperture (Ac) has units of ft2.
4.4.1.2
Projected area. In order to analyze sunspaces that have tilted
glazings, it
is necessary to know the area of the collector that is
projected on
a vertical plane. The tilt relative to vertical is given by
[theta], and
the required relationship is:
Ap = Ac [multiplied by] cos ([theta])
(Equation 4.8)
The projected area (Ap) should be used in place of Ac for design
analysis work on sunspaces.
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