Development of Computer Models for Simulating the Optimum Design Parameters of a Passive Solar Heating Chicken Brooder System

Brooding refers to early periods of growth when chicks require supplementary heat to maintain their normal body temperature. Generally, chicks kept in environmental temperatures outside their comfort zone suffer low growth and high mortality rates. Solar energy has a regular daily and annual cycle, and is unavailable during periods of bad weather. Hence requires special storage and distribution of the energy different from the utilization of conventional energy sources. In this study computer models were developed for simulating internal brooder envelope brooding Temperatures and ammonia gas concentration in ppm. Further, analysis was carried out to determine the influence of trombe wall thickness on the variation of hourly internal brooder temperatures for various months of the year. The trombe wall thickness were set at 100,150, 200, 250 and 300mm and hourly temperatures simulated using Matlab computer program. The wall thickness of 100mm and 150 mm yielded maximum brooding space temperature of 36.50C and 35.30C respectively. The resultant brooder temperatures were above the optimal brooding temperature range of 340C for day one and 21 to 240C for the 28th day of brooding. However, the lowest brooder temperatures attained for 100mm and 150mm wall thickness were 29.50C and 30.80C respectively. The wall thickness of 300mm yielded temperature range of 25.70C to 280C.From this study it is deduced that the wall thickness of 100 and 150mm are suitable for development of a chicks' brooder. Though, supplementary source of heat will be required to keep the birds comfortable for the first one week of brooding period. The brooder pH was set at 10 and the ammonia concentration simulated for 28 days at brooding floor temperatures of 14.80C, 18.70C, 22.60C and 27.40C.The results were that the ammonia concentration increased exponentially from day one to the 28th day of brooding for all the floor temperatures. The highest emission of ammonia was recorded at the temperature of 14.80C for the first fifteen days; but after the 15th day the temperature of 18.70C recorded the highest emission of ammonia. Conversely, the temperature of 27.40C yielded the lowest ammonia emission. Therefore, it is essential in the design of brooders to have provision for facilitating removal of birds' droppings to minimize emission of the ammonia gas from the floor of the brooder.