A hydronic HVAC system consists of a boiler or chiller, pumps, pipes, and heat exchangers. The boiler or chiller heats or cools water, which is then circulated through the pipes to the heat exchangers, such as radiators, convectors, or fan coils. The heat exchangers transfer the heat energy to the conditioned space. Hydronic systems can be more efficient and comfortable than air-based systems, especially in applications with high heating or cooling demands. They also offer design flexibility and can be used in conjunction with other HVAC systems.