The objective of this work is to assess the combined effects of fixed
pressure drop and specific air mass flow rate on duct dimensions (leng
th and depth) of single-pass-with-bare-plate, single-cover and double-
cover solar air heaters, and to obtain the resultant system efficiency
that corresponds to a pre-fixed pumping cost and a minimum material c
ost per unit area of the system. The design selection methodology adop
ted in this paper will make it feasible for an air-heater designer to
construct efficient and economical solar air heaters.