The solar collector consists of insulator, absorber and
cover glass. The length, the width and the total volume of the
collector are 2 m, 1 m and 0.28 m3, respectively. The 0.004 m
thick transparent glass cover was placed 0.05 m apart the
absorber. The 0.001 m thick corrugated absorber was placed
0.04 m apart the insulator. The 0.05 m thick polyurethane
insulation, with heat conductivity 0.028 W/m K, is placed in
the bottom of the collector to decrease thermal losses through
the bottom. There are two air gaps between cover glass and
the absorber and between absorber and insulator through
which ambient air is sucked by a centrifugal fan from lower
side of the collector to the greenhouse. The solar collector was
oriented full south and inclined 37° to horizontal plane.
The experimental greenhouse occupy a floor area equal to
14.8 m2, 3.7 m wide, 4 m long and 3 m high at the center. The
greenhouse walls and roof are covered by plexiglass with