In the global solar thermal energy market, the dominant markets are China, Europe, Japan and India. Designs that are suitable for hot climates are made simpler and cheaper, and can be considered a suitable technology in these places. So residential solar water heater is also more and more, but how does residential solar water heater work?

Due to the continuous lack of resources, countries have begun to develop new resources. Solar energy is another major resource that has been discovered. Today, solar water heaters are gradually being applied to a variety of people. As a result, a variety of residential solar water heater have appeared on the market.

Solar water heaters are heating devices that convert solar energy into heat energy, heating water from low temperature to high temperature to meet the hot water use of people in life and production. The residential solar water heater is composed of heat collecting tubes, water storage tanks and brackets and other related spare parts. The conversion of solar energy into heat energy mainly depends on the vacuum heat collecting tube, and the vacuum heat collecting tube uses the principle of hot water floating on the cold water sink to make the water generate microcirculation. Hot water is required. Residential solar water heaters still require professional staff to install.

​Solar energy is a huge energy that people can use in nature. The growth of all life on Earth is related to solar radiation. In recent years, many countries are exploring effective ways to use solar energy. With more and more solar water heaters being invented and widely used, the performance of residential solar water heaters has attracted more and more attention. This paper briefly analyses the advantages of residential solar water heater compared with other water heaters, and the heat transfer efficiency between residential solar water heater and the sun, atmosphere and environment.