Wide variations in temperature and humidity on hot summer days can present problems for conventional fogging systems. Systems with set water flow rates in liters/hour (gallons/hour) often apply too much moisture at one time of day, while not enough at other times. Typically, broiler houses use two fogging lines with a 7.6 L/h (2 gal/h) nozzle at 6 m (20 ft) intervals. While some newer houses use extra lines sequenced with thermostats, a mismatch often exists during the day between the water addition rate and the amount of water the air can actually evaporate. This article describes a computer-controlled, variable-rate fogging system that had extra lines with a variety of nozzles and a motorized valve in the discharge of the booster pump. The arrangement gave a wide range of water flow with an almost infinite number of discrete flow rates. Results indicated an ability to maintain interior temperatures at somewhat of a “plateau” during midday. On a hot day with near 38°C (100°F) and 32% relative humidity, the system could reduce interior temperatures by as much as 6.6°C (12°F) below ambient.