Abstract
In this article, a single-circuit solar water heater with a thermosiphon was built, tested and numerically modeled in Kazakhstan, Almaty. To heat cold water in the south-eastern region of Kazakhstan, a flat solar collector was developed and studied, as well as a mathematical model of a single-circuit solar installation with a thermosiphon. In this mathematical model, the Bernoulli equation was used to solve the water flow in the dispenser tank and in the collector itself. Numerical modeling in MatLab was developed using a mathematical model. The dependences of the temperature inside the solar collector, which is usually distributed inside the collector in accordance with the law of thermodynamics, were obtained, and the maximum relative humidity, which was 75%, was also solved. In the course of the study, the annual change in the efficiency of the system was decided.