In terms of collector form, it is also divided into vacuum tube header-type collection and distribution systems and flat plate collection and distribution systems. Compared to the collection and distribution system,

instead of each household having a heat exchange water tank, a large water tank is installed on the rooftop to store hot water, which is then supplied to each household. The hot water usage for each household

is individually metered.

This project is equivalent to supplying commercial hot water to each household, with individual metering. The advantage lies in the high efficiency of hot water application—those with higher demand use more, while those with lower demand use less, preventing resource waste. Additionally, with commercialized individual metering, it enables the commercial sale of hot water.

The drawback is that if the residential occupancy rate is low, even if only one household uses hot water, the entire system must operate, resulting in significant waste. Furthermore, the load-bearing design for the rooftop water tank location requires special consideration.