The feasibility study of the solar heat pump combined system for the production of hot water in Laos

This study investigates the sustainability of solar collectors and heat
pump systems for the production of sustainable hot water. The lat-plate solar
collector with a single glass panel, copper tubes and black absorbers was tested in
a size of 4 m
2
 at different water low rates(15 L/min, 17.5 L/min, 20 L/min) to 200
L. The 3,300W heat pump is equipped with a 25-plate heat exchanger and 370W
water pump. The optimal low rate at the time of heating was determined at 17
litres per minute. This rate achieved a thermal pump eficiency of 5.1%, which
allowed water to heat up to 50°C in 24 minutes and cost 1,400 LAK. The system
can produce water up to 50 °C with a capacity of 800 litres. Comparing economics
to conventional coil water heaters, the system's initial cost (15,234,500 LAK,
9,566,000 LAK) is higher, but offers signiicant energy savings (81.4% annual
savings), a ive-year repayment period, and 31.8% Internal Rate of Return (IRR).
Despite initial investments, this system offers promising options for eficient and
sustainable production of hot water.