In terms of the form of the collector, it is divided into a vacuum tube header-type collection and distribution system and a flat plate collection and distribution system. This refers to a system where the collectors are uniformly installed on the roof, each household is equipped with a water tank with an internal heat exchanger, and the water in the tank is heated through circulation pipes.

The advantages of this system are: the collectors are installed on the roof, providing good lighting effects. Additionally, it does not occupy the south wall facade, which is beneficial for the wall structure and exterior appearance. This circulation design follows the same principle as heating systems and is a standard design in HVAC, making it easy to produce drawings.

The disadvantages of this system are that at a minimum, one unit requires one circulation system, or it can be designed with several units sharing one system. This prevents independent control, meaning even if only a few households are occupied, the entire system must be fully operational, leading to energy and operational waste. Additionally, the long circulation pipes result in significant waste. Moreover, operating the circulation pump requires energy and incurs operational costs.