The 12 new environmental chambers for poultry research recently completed at the University of Arkansas feature solid state electronic systems to control dry bulb temperature and dew point of the chamber air. Dry bulb temperature is controlled by reheating previously cooled and dehumidified air by an electric heater installed in each supply air duct. Solid state controls proportion the flow of electricity to the heater to match the demand. The system is arranged to maintain constant temperature on a diurnal temperature cycle. A solid state time-proportioning control maintains a preselected dew point in each chamber. The control operates a solenoid valve to admit steam in regular pulses of varying duration to add moisture to the supply of air as needed. Automatic systems to control drinking water temperature and air flowrate also are included. The use of electronic controls, with electric heat, has resulted in environmental control systems of high precision with minimal mechanical complexity. The chambers are being used to study the response of broilers to different brooding temperature schedules and drinking water temperatures.
Rokeby, T.R.C; Nelson, G. S.; and Harris, G. C. Jr.
"Bioclimatic Chambers for Poultry Research: Design and Preliminary Results of Testing,"
Journal of the Arkansas Academy of Science: Vol. 26
, Article 15.
Available at: http://scholarworks.uark.edu/jaas/vol26/iss1/15