Abstract: A chicken or fowl grow out facility utilizes a ventilated floor assembly including a ventilated floor through which liquid and gas can flow, but which retains manure deposited thereon, and a closed bottom floor plenum underneath the ventilated floor, which includes a liquid and vapor barrier covering the ground surface. Blowers in an attic plenum can discharge warm air through hanging pleated conduit tubes into the floor plenum to provide heat through the ventilated floor. A plurality of indirect evaporative coolers and associated air blowers in the facility walls force outside air, cooled or uncooled, into the growth facility, and create higher pressure in the growth facility than the pressure in the floor plenum. Vacuum blowers associated with the floor plenum cause the flow of air and air-borne contaminates through the floor and exhaust same from the plenum to outside the facility which dries manure on the floor and reduces ammonia formation and pathogen growth.