Mar., 1938] Electric Brooding of Chicks, II. Heat Requirements 11 



CASE I 52" SQUARE BROODER 



CASE I 56' ROUND BROODER 



Fig. 4. Square and round type brooders, one having a center exhaust venti- 

 lation and the other edge exhaust. Thermocouple readings show the heat dis- 

 tribution with a full load of chicks taken under brooder house conditions. 



giving rise to the possibility of recirculation effects in the upper layers 

 and a greater degree of floor draft effects at the outer edge at floor level. 



Case 2 with 5-weeks old chicks showed temperature regulation hori- 

 zontally that was quite flat and regular in the center but reflected the 

 shape of the ceiling. The temperature at the floor edge of curtain was 

 more stable and showed 10 degrees less variation than in the first case. 

 This indicates that floor drafts gave less trouble. 



With the different types of design which are employed, there natu- 

 rally follow different operating characteristics. While it is generally 

 presumed that a uniform temperature under the hover is necessary, 

 there is evidence that a certain variation may be desirable to suit the 

 varying needs of different individuals. Whether this regulation should 

 be varied horizontally, vertically, both, or not at all is not clear with 

 present available information. 



There was a vertical change in temperature within 31/^" of floor of 

 30 degrees in the square and 20 degrees in the round brooder. 



The failure to find any substantial benefit from special floor insula- 

 tion points to the effect of floor drafts, brooder design and other sources 

 of irregularities, as causes of the differences. 



The above comparisons of heat regulation are, therefore, of value 

 principally to determine the effect of different locations of out-take 

 flues, heating elements and shapes of brooding space, on the contours of 

 heat levels and provide information on brooder design factors. 



Under-Brooder Floor Temperatures 



Figure 5 shows cross sections of the floor construction in the four 

 houses. 



All indications to date point to the necessity of considering the 

 brooder house floor as composed of two parts : (1) that part of the floor 



