The office and residential buildings are typically situated in a concentrated manner in metro areas, and the air-conditioning load of these buildings is massive, with a long running time. These buildings also share similar features, and a centralized cold-heat source air conditioning could reduce the equipment capacity need and operation cost. By analyzing the air-conditioning load characteristics and balancing the contradictions of short-term and long-term loads, a water system scheme is proposed where cold-heat sources equipment is established separately, with a combined pipe network that could be used as an alternative. By combining the characteristics of two types of loads, the developed equipment configuration has two types of equipment that could be used as alternates to each other to improve the stability of daily operation and adaptability to various working conditions of the water system. The pipeline network adopted a regionalized two-pipe one-pump constant flow system, and the pumps and water chillers were arranged in opposite-side pairs, hence the free space between equipment could be used for repair space or for water chillers inspections, which could reduce the size of the equipment space needed. Based on design interfaces and civil engineering supporting requirements, power supply, automatic control, and other air-condition design matters, the specifications, quantities, installation location and assignment of supporting facilities, and air conditioning water system accessories such as valves and instruments could be defined and enabled to coordinate with an automatic control system.