Operating the drying system in hybrid mode (Fig. 8)
leads to intermittent behavior, due to the fact that neither
solar nor LP combustion energetic contributions are constant,
as a result of the transitory nature of solar radiation
and the intermittent operation of the LP gas burner. Temperature
in the interior of the drying chamber remained
between 50 and 60 C, and efficiency varied within the
range of 8–71% throughout experimentation.