Experimental and theoretical investigations were conducted to evaluate the uniformity of cool air discharge along a perforated distribution tube for zone cooling in a greenhouse. The calculated static pressures in the tube agreed well with the experimental results. Air temperature in the tube was calculated by considering a constant overall heat flux through the tube wall along the tube length. A good agreement was obtained between the calculated and measured air temperatures in the tube. The coupled analysis of air flow and heat transfer was used to simulate the uniformity of cool air discharge for practical input variables. Furthermore, the relationships between the uniformity of cool air discharge and the design parameters of the tube were obtained.