Page 318 - Handbook of Energy Engineering Calculations

Flat-plate collectors should face south for maximum exposure and should be
tilted so the sun’s rays are normal to the plane of the plate cover. Figure 5
shows the optimum tilt angle for the plate for various insolation requirements
at different latitudes.

FIGURE 5 Spacing of solar flat-plate collectors to avoid
shadowing. (Power.)

Since Jacksonville, Fl, is approximately at latitude 30°, the tilt of the plate
for maximum year-round insolation should be 25° from Fig. 5. As a general

rule for heating with maximum winter insolation, the tilt angle should be 15°
plus the angle of latitude at the site; for cooling, the tilt angle equals the
latitude (in the south, this should be the latitude minus 10° for cooling); for
hot water, the angle of tilt equals the latitude plus 5°. For combined systems,

such as heating, cooling, and hot water, the tilt for the dominant service
should prevail. Alternatively, the tilt for maximum year-round insolation can
be sued, as was done above.
When collector banks are set in back of one another in a sawtooth

arrangement, low winter sun can cause shading of one collector by another.
This can cause a loss in capacity unless the units are carefully spaced. Table 1