This heated water warms radiators placed in the rooms. These radiators, in turn, warm the air in the room. In some homes, pipes are buried in the concrete slab. This is type of system is called radiant heat. Hot water heat has made steam heat obsolete in homes and smaller buildings.
Water is heated in a boiler until it becomes steam.
Steam, which is a gas, rises through the pipes into radiators. The steam causes these radiators to become hot. These radiators warm the air in a building. Steam heat is noisy, and buildings with steam heat often warm unevenly. The pipes used with steam heat have a long life expectancy, and the piping typically used for steam system is not readily converted to hot water heating systems .