Mar., 1938] Electric Brooding of Chicks, II. Heat Requirements 



The insulated floor of one house. A piece 

 of the insulating board stands at the left 

 ready to be slid into place under the 

 black waterproof envelope before it is 

 sealed with tar. Thermocouple junctions 

 are located under the adhesive tape 

 squares and carried to a connecting 

 panel. 



Heated Floor 



The double wood floor showed 

 the least tendency to vary in ex- 

 tremes. The average tempera- 

 ture up to Thursday mid-morn- 

 ing is higlier on the insulated 

 than the non-insulated floor, but 

 instead of leveling out, the fluc- 

 tuations seem to increase. 



There is also an easily seen re- 

 lation between the outside tem- 

 perature of the first of the week, 

 (shown by the lower curve), 

 and the insulated floor. It should 

 be emphasized that the two floor 

 curves were taken in two separ- 

 ate houses simultaneously and 

 that they follow each other close- 

 ly in the nature of their fluctua- 

 tions. 



The main irregularities in tem- 

 perature are obviously caused by 

 sources outside the brooder, by 

 brooder design features, by floor 

 drafts, etc. Chick movement 

 seems to coincide with, or be 

 caused by, the extremes in these 

 fluctuations.* 



On Friday noon, an electrically heated floor pad (60 w. capacity, 

 operating continuously) was placed under the brooder on top of the 

 uninsulated floor. The anticipated return of cold weather did not 

 transpire, and the floor temperature shot up beyond all reasonable 

 values (record off the chart on Friday night). 



This pad was inserted without changing the amount of heat over- 

 head in the brooder, showing that excessive heat can be responsible for 

 high extremes in the temperature curves, as might be expected. 



Effect of Ventilation 



The same effect was brought about, however, in the house with the 

 insulated floor on Saturday and Sunday by not opening the ventilator, 

 showing that ivithout additional heat, restriction of ventilation may 

 also result in excessive temperatures. 



The three makes of brooders show a considerable degree of variation 

 when compared on the basis of the relation between the intake area 

 (curtained edge of brooder) and the area of exhaust flue opening. 

 (Table III) Similarly wide variations may be seen between the ex- 



See Page 14, "Effect on Floor Under Brooders." 



