Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

Table 6

Experimental performances of all-glass vacuum tube solar water heaters with collectors at down slope placement and at reverse slope placement.

Date	Reverse slope placement			Down slope placement
	Feb. 3	Feb. 4	March 1	Jan. 29	Jan. 30
Ambient average temperature (°C)	17.1	16.8	20.3	14.8	15.6
Average wind speed (m/s)	1.2	1.4	0.3	1.6	0.7
Irradiance (MJ)	20.2	20.6	19.2	19.7	20.6
Time (hr)	6.0	6.0	6.0	6.0	6.0
Initial temperature of tank (°C)	27.7	14.3	16.9	12.0	19.6
Final temperature of tank (°C)	49.9	38.7	40.7	45.2	43.6
Tank volume (L)	120	120	120	120	120
Temperature rise (°C)	22.2	24.5	23.8	33.2	24.0
Efficiency	0.419	0.453	0.471	0.641	0.617