STEAM HEAT IN THE HOME 195 



the metal to the outside surfaces. Air coming in contact 

 with the radiators is heated, and this heat is given to 

 other objects in the room by convection, while some heat 

 is radiated directly to the walls and objects in the room. 

 Thus the room is heated by convection more than by 

 radiation, and we have a more even distribution of heat 

 than by stove or by steam. One drawback to the hot- 

 water system is the fact that in the sleeping rooms we 

 cannot cut off the heat without danger of freezing the 

 water in the radiator. The best plan for those who like 

 to sleep with the windows open is to cover the radiator 

 at night with a heavy blanket or some good non-conduct- 

 ing substance. 



Advantages and disadvantages of hot water. This is 

 one of* the most expensive systems to install, but it is more 

 economical to operate than the hot-air furnace or the stove. 

 With it the rooms may be kept at an even temperature, 

 but unfortunately, if the water gets cold it takes a long 

 time to warm it up. As the system provides no ventila- 

 tion, we must secure fresh air in some other way. An ex- 

 cellent system is the combination of hot water and hot air, 

 in which the boiler is situated in the top of the furnace, 

 and the water thus heated is passed to rooms far distant 

 from the furnace. 



Steam heat in the home. In the steam-heating systems, 

 the parts are practically the same as in the hot-water 

 system, except that there is no expansion tank and the 

 pipes are closed throughout. Steam made by boiling water 

 passes through the pipes to the radiators. In the radiators 

 the steam condenses, giving off its load of heat. The 

 water formed by this condensation leaves the radiator and 

 is brought back to the furnace again, either by a system 



