CHAPTER LXXXIV 

 VENTILATION OF FARM BUILDINGS 



Importance of Ventilation. One of the most important 

 features involved in the design of farm buildings is that of 

 ventilation. It is generally recognized that men and animals 

 must have fresh air, and the most favorable conditions for 

 life and health are attained when the air is as pure as the open 

 atmosphere. It is not practical to provide air as pure as this 

 to animals housed in buildings designed primarily for shelter 

 and warmth. 



The Standard of Purity. The standard of purity, or the 

 extent to which pure air may be vitiated with expired air and 

 still be fit to breathe, is a much-argued point. For conven- 

 ience, the purity of air is designated by the number of parts 

 of carbon dioxide in 10,000 parts of air. Pure air contains 

 about four parts of carbon dioxide in each 10,000 parts. 



De Chaumont, an authority on ventilation, holds that six 

 parts of carbon dioxide in 10,000 parts of air should be the 

 standard, and other authorities recommend various and 

 greater amounts. The late Professor F. H. King, of Wiscon- 

 sin, recommended 16 parts as the correct standard, but em- 

 phasized the great need of experiments to determine definitely 

 the correct standard. There is little doubt that if this lower 

 standard were maintained generally, ventilation conditions 

 would be much better than they are now. 



Purpose of Ventilation. The purpose of ventilation is 

 threefold: (1) To supply pure air to the lungs of the animals; 

 (2) to dilute and remove the products of respiration; and (3) 

 to carry away the odors or the effluvium arising from the 



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