All equipments were connected to a pipe in which hot
water could flow within a closed loop. It was concluded
that the SWHS itself acted as a solar water pump. The
experiment was tested for discharge heads of 1, 1.5, and
2m. The discharge head is the difference between the liquid
levels of the OT and the water ST. All data were collected
during 8:00–17:00 at the School of Energy Environment
and Materials, King Mongkut’s University of Technology
Thonburi.
The vapor gage pressure inside the solar collector
represents the pressure difference between the collector
and the OT tank when the OT pressure always is equal to
one atmosphere. This vapor gage pressure could be
measured by a pressure transducer (Cole Parmer) with
accuracy 70.25%. Eleven sets of K-type thermocouple connected to a hybrid recorder (Yokogawa) were used to
measure temperature of the surrounding air, water, and
vapor at the OT, the collector, and the ST with accuracy
70.5 1C. Wind velocity was measured by a hot-wire
anemometer with accuracy 70.2 m/s. Solarimeter (Kipp
& Zonen) was used to measure solar irradiation with
accuracy 72W/m2. The measurement points are shown in
Fig. 2.