Explain why heat systems based on the circulation of steam are more efficient in warming a building than those based on the circulation of hot water.

Hint:For people that are inhabitants of places with extremely cold climate, a central heating system provides warmth to the whole interior of a building (or a portion of the building). The heating system is usually combined with other systems such as heating, ventilation and air conditioning systems.

Complete step by step answer:
In a steam heating system, a boiler furnace heats water utilizing gas or oil-fired burner and turns it into steam. The steam travels through pipes to radiators or convectors, which give off heat and warm up the room. As the steam cools, it condenses back into the water, and returns to the boiler to be heated again. The latent heat of condensation of steam is much higher than the specific heat capacity of water, hence for the same change in temperature of the steam and hot water, the heat released by steam is more than the heat released by hot-water. Steam heating systems have fewer moving parts, making them more reliable and durable. Another major advantage of steam heating systems is their long life and trouble-free operation.

Steam entering the radiator condenses and gives up its latent heat, returning to liquid water. The radiator, in turn, heats the air of the room and provides some direct radiant heat.

Note:Alternatives to steam heating systems include central solar heating, gas heaters and district heating. District heating uses the wastewater from an industrial process or electricity generating plant (being circulated using underground piping) to provide heat for neighbouring buildings.