Spray nozzles atomize the liquid stream by high velocity compressed air to create a range of 20 to 200 micron-size spray droplets. Droplet size and production is not dependent on liquid pressure. The ultra-fine droplet-sized sprays accelerate air-liquid interaction to facilitate effective cooling, and the smaller droplets expose more surface area to increase the evaporation rate. Three types of spray nozzles are offered: fogging, atomizing and humidifying. The fogging nozzle produces a directed spray with droplet sizes of 20 to 60 microns, a flow rate of 0 to 30 gal/hr and liquid viscosities up to 1100 cPs. The atomizing nozzle produces a directed spray of 60 to 200 microns, a flow rate of 0 to 30 gal/hr with liquid viscosity up to 1100 cPs. The humidifying nozzle produces a wide spray with droplet sizes of 20 to 200 microns, a flow rate of 0 to 15 gal/hr, and liquid viscosity up to 100 cPs.