Maintaining good production quality in layer poultry houses is directly correlated to the thermal environment of the laying hens as well as their breathable air quality. This work compares the performance of two passive cooling systems in meeting the thermal and indoor air quality requirements (CO2, water vapor and NH3) in a layer house in Doha, Qatar characterized by a semi-arid climate. The first system is a standalone cross flow dew point evaporative cooler (DPIEC) supplying air through a localized air distribution system. The second system is a DPIEC aided by a radiative cooling (RC) panel that pre-cools the supply fresh air, in an effort to reduce the system sizing, air and water consumption even further. To achieve these objectives, a modular analysis was adopted, where mathematical models were developed for the DPIEC and RC systems and the poultry house module conditioned by the localized system. A 3D CFD model was developed for the compartment conditioned by the localized system. The DPIEC was sized and the hourly variation in needed supply fresh air and water was determined for the critical month of May, June July of the summer season.