4o8 



ENGINEERING ON THE FARM 



Wordier 



S-/o7-/t/tr 



in Figure 313, will increase the rapidity of air circulation, 

 since only the air within the jacket is heated. This air 

 becomes hotter and rises faster, thus making a more rapid 

 circulation and a more efficient heating system. The objec- 

 tions to this sheet-iron jacket are that the stove proper gets 



so hot that the air is burned 

 (dried to excess) in passing up 

 through, and the cleaning and 

 firing are difficult owing to the 

 distance through to the fire box. 

 Another device is a drum or 

 radiator attached to the smoke 

 pipe just over the stove or in 

 an upstairs room (Fig. 314). 

 It is a simple device for in- 

 creasing the size of the pipe for 

 a short distance, thus allowing 

 more heat to leave the smoke 

 and remain in the room. 



Hot-air furnace. A stove with 

 a jacket, placed in the cellar, 

 becomes a furnace. A brick wall 

 may be substituted for the steel 

 jacket. A return flue through 

 the floor some distance from 

 the furnace makes the system 

 complete. Such a scheme is 

 used for many churches and 

 assembly rooms where the base- 

 ment can be used as a furnace 

 room. This method is now 

 known as the pipeless furnace. 

 When this furnace is set a little lower in the ground and 

 the neck is divided into several small pipes, it may be used, 

 as shown in Figure 315, to heat several rooms. Heat is 

 conducted to the second-floor rooms by rectangular pipes 



<jb/.o/4m 



Cold Am 



After University of Minnesota 



Fig. 314. Drum for extracting 



heat from smoke. The drum is 



placed above the stove or on the 



second floor before the pipe 



enters the chimney. 



