HEATING BUILDINGS 



101 



wood, coal, or gas heats the room by radiation. The 

 floor, walls, and objects in the room are heated directly 

 by radiation, and they in turn warm the air because the 

 air comes in contact with them. 



When stoves are used all three methods of heat transfer 

 are brought into action. 

 The fire in the stove 

 heats the iron. This 

 heat is carried through 

 the iron to the outside 

 surface by conduction. 

 A large part of the 

 stove's heat passes to 

 the objects in the room 

 by radiation, and they 

 in turn warm the air. 

 Much air also comes in 

 contact with the hot 

 stove and is heated by 



conduction. After it is heated it is forced upward 

 rapidly by the cooler air coming toward the stove. So 

 there is a continuous current of air rising over the stove 

 toward the ceiling. It flows along the ceiling to the 

 walls, where it is slightly cooled, and descends to the 

 floor and goes to the stove again. 



The illustration represents the heating of a schoolroom 

 by the use of a stove. The fresh air from the outside 

 goes through a duct to the base of the stove, where it is 

 heated and forced to the upper parts of the room by 

 the inflowing cold air. The warm air gradually cools 

 and drops to the floor and moves through the impure 

 air ducts. By this method the greater part of the room 

 is heated by convection. 



CIRCULATION or AIR WITH A STOVE 

 IN A SMALL ROOM 



