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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