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 heatpump systems for the production of sustainable hot water. The lat-plate solarcollector with a single glass panel, copper tubes and black absorbers was tested ina size of 4 m2 at different water low rates(15 L/min, 17.5 L/min, 20 L/min) to 200L. The 3,300W heat pump is equipped with a 25-plate heat exchanger and 370Wwater pump. The optimal low rate at the time of heating was determined at 17litres per minute. This rate achieved a thermal pump eficiency of 5.1%, whichallowed water to heat up to 50°C in 24 minutes and cost 1,400 LAK. The systemcan produce water up to 50 °C with a capacity of 800 litres. Comparing economicsto 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% annualsavings), a ive-year repayment period, and 31.8% Internal Rate of Return (IRR).Despite initial investments, this system offers promising options for eficient andsustainable production of hot water.