Water separator is a water container through which the single way water is divided into several output devices and water collector is a catchment device through which multi-way water is merged into one way water. On the one hand, water collector distribute the water flow in main pipe as necessary to ensure the flow of regional branch of loop to meet the load, on the other hand, water separator converge each branch of water flow into together and return into water trunk pipe to cycle operation. This way of return water re-use could achieve more efficent results and it can also meet the needs of heating and cooling.