CONSTRUCTION OF CREAMERIES 41 



and quick removal of free steam, to efficiently expel foul air, 

 and to facilitate the regulation of temperature. Unless the 

 masses of free steam which befog the atmosphere daily in every 

 creamery, find a ready exit, and are expelled from the factory 

 quickly, they will condense, and cause the walls and ceiling to 

 sweat and drip and rot or corrode, the motors, belts and other 

 equipment to deteriorate, and mold growth to develop on walls 

 and ceilings and supplies. This is especially the case during the 

 winter months. The removal of foul air and the control of the 

 temperature of the air are essential for the comfort, health and 

 maximum efficiency of the employees and for the protection 

 of the product against deteriorating contamination. 



The system of ventilation best suited to accomplish this 

 must of necessity vary with the location, type and size of the 

 building and the arrangement of the machinery. In the small, 

 one-story building, with a high roof, a well-made sky-light with 

 a steep slope of the side roofs, toward the sky-light, may prove 

 fairly efficient, especially where an effort is made to place the 

 equipment that gives off the free steam as directly under the 

 sky-light ventilator as possible. 



In large creameries with more than one story the sky-light 

 system is seldom feasible. Nor is gravity ventilation, under 

 average conditions, adequate to produce satisfactory results, in 

 creameries where there is bound to be much escape of free steam. 

 In gravity ventilation, the circulation and exchange of air de- 

 pends exclusively on the difference in temperature between the 

 atmosphere on the inside and outside of the creamery. This 

 fails to produce a sufficiently rapid exchange of air to remove 

 the free steam before it condenses, especially in cold weather. 



It is necessary, therefore, to provide for some form of forced 

 ventilation. Under certain conditions the use of the chimney 

 may furnish the needed draft. In this case an outer chimney 

 is built around the smoke stack proper, with an air space be^ 

 tween the two stacks, and one or more ventilating flues in- 

 stalled in the creamery and terminating in the jacket between 

 the two chimney shafts, provides the exit for the air in the 

 creamery. 



Under many other conditions, however, it becomes neces- 



