2009 Annual Report 1a.Objectives (from AD-416) The objectives of this research are to evaluate energy usage patterns in modern broiler housing throughout the production cycle and to determine the effects of energy saving measures on thermal conditions and production efficiency in broiler chickens during the brooding phase. 1b.Approach (from AD-416) Effects of reduced energy usage regimens and measures to improve energy efficiency in modern broiler housing on the thermal environment and subsequent production efficiency will be evaluated. 3.Progress Report Energy usage levels for evaporative cooling were measured in a commercial broiler facility. For the tested configuration, fan power requirements averaged 1.3 kW and evaporative cooling system pumps averaged 1 kW. Further inspection showed that evaporative cooling pumps represented 18% of energy usage required to cool a commercial broiler house. Fan power requirements were stable with time, but varied from fan to fan with a range of 1.0 kW to 1.5 kW. Time-averaged power requirements were found to be sufficiently accurate when compared to instantaneous readings for power use estimations. One presentation entitled, “Energy Use and Partitioning in Commercial Broiler Production” (J.L. Purswell and J.D. Davis) was presented at the 2009 ASABE Annual International Meeting in Reno, NV in June 2009. This project is monitored via phone calls, emails, and direct visits.