The solar water heating system includes solar collector, circulation system, control system, auxiliary energy system, heat storage system, support frame and other parts. So far, the combination of solar water heating systems and residential building exteriors in China has roughly gone through four stages of development.

1. Rural housing alone installation

China’s solar water heating system first started in rural areas, and the most widely used ones are smouldering water heaters and compact solar water heaters. Its structure is simple and cheap, and each household is independently installed on the roof (see Figure 1). Because the shape of rural houses is messy and random, and the requirements for aesthetics are not high, although the collectors installed on the roof are obtrusive, they are scattered.

2. Town house installation alone

Compact solar water heaters are widely used in urban dwellings. Most of the urban residences are collective residences, and the overall image of the city also puts forward higher requirements for the appearance of the buildings. However, due to the lack of unified management and guidance, households install themselves, and solar collectors of different forms, specifications and positions are installed on the same house, and the pipes are randomly broken through the walls and criss-crossed on the roof and façade, seriously damaging the appearance of the original house.

3. Integrated installation of rural houses

With the rapid development of the solar energy industry and the increase in the demand for solar water heating systems, real estate developers have begun to try engineering operations. The solar water heating system of a residence is selected and installed by the developer. But its combination with the architectural appearance is still in the low-level stage. The most used are compact solar water heaters, which are neatly arranged on the roof of the building (see Figure 2).

4. Integrated installation of urban housing

The collector and the water tank of the compact solar water heater cannot be separated, and there are always problems in combination with the appearance of the building. With the advent of the split solar water heating system, the degree of integration between the solar water heating system and the appearance of residential buildings has been greatly improved. The design of residential buildings takes into account the installation location and piping arrangement of the solar water heating system. Solar collectors can be organically combined with building roofs, facades and other parts (see Figure 3).

At present, the installation of solar water heating systems in the vast majority of China is still in the first three stages of development, and a few provinces and cities with rapid development of solar water heating industry, such as Shandong, Yunnan, Zhejiang and other places, have started the fourth stage of start and development.

Read more: The development trend of solar water heating system in China