Experimental Study of a Novel Direct-Expansion Variable Frequency Finned Solar/Air-Assisted Heat Pump Water Heater

Table 1

Parameters of evaporator-collector.

Length	1475 mm
Width	800 mm
Solar absorptivity of selective absorption coating	0.95
Transmittance of glass plate	0.85
External diameter of copper tube	9.52 mm
Thickness of copper tube	0.35 mm
Number of tube rows	16
Thickness of fin	0.35 mm
Punching diameter of fin	10 mm
Height of fin	15 mm
Vertical pitch of fin	3 mm
Number of fins	208
Angle of fin and copper tube	28°