SOME FUNDAMENTALS OF STABLE VENTILATION 
By Henry Prentiss Armsby, Director, and Max Kriss, Associate, Institute of Animal 
Nutrition of the Pennsylvania State College 
COOPERATIVE INVESTIGATIONS BETWEEN THE BUREAU OF ANIMAL 
INDUSTRY OF THE UNITED STATES DEPARTMENT OF AGRICULTURE 
AND THE INSTITUTE OF ANIMAL NUTRITION OF THE PENNSYLVANIA 
STATE COLLEGE 
Much study has been given in the past to the mechanical aspects of 
stable ventilation and to the construction of efficient systems; but, so 
far as the authors are aware, singularly little attention has been paid to 
the amount of motive power available for the operation of these systems. 
This is particularly true of that portion of it which is derived from the 
heat production of the animals, notwithstanding the fact that the latter 
may vary within wide limits and may at times constitute the sole motive 
power. 
In the cooperative investigations upon animal nutrition which have 
been carried on at this institute during the past 20 years, a large number 
of direct determinations of the heat production of cattle under different 
conditions have been made. Numerous similar determinations have 
also been made by Kellner (rr, 12,1 j ) 1 by the method of indirect calorim¬ 
etry. A smaller number of results upon other species of farm animals 
are also on record. Upon the initiative and with the efficient coopera¬ 
tion of Mr. W. B. Clarkson, chairman of the Committee on Farm Build¬ 
ing Ventilation of the American Society of Agricultural Engineers, we 
have attempted to work out a method by which these results may be 
applied to the problems of stable ventilation and the heat production 
in any specific case computed with a fair approximation to accuracy. 
The present paper contains the results of these endeavors. 
INTRODUCTION 
The installation of an effective ventilating system must necessarily 
depend, first, on a knowledge of the scientific principles involved and, 
second, upon a study of the conditions of each individual case. As the 
amounts of pure air required by the different species of farm animals are 
different, the minimum volume of air movement through a stable must 
vary accordingly. The construction of a ventilating system must be 
based on the unit of air movement chosen and on the available motive 
power which is to ensure the required supply of air. 
1 Reference is made by number (italic) to ‘‘Literature cited,” p. 367-368 
Journal of Agricultural Research, 
Washington, D. C. 
xz 
Vol. XXI, No. s 
June 1, 1921 
Key No. Pa.-u 
42269°—21-5 
(343) 
