Disadvantages of Misting and Fogging
By using a high capacity, coarse droplet soaker nozzle, enough water can be applied to fully wet the cows to the hide. The water is then allowed to evaporate, which pulls heat from the animal, just like sweating. Increased air movement across the wet hide, provided by fans, makes this system most efficient. Proper control is critical to ensure that the cow gets soaked to the hide along the topline, while not getting wet to the point of having water running off her sides (see photo "Proper Degree of Wetting Cattle").
Mist and fogging nozzles have been used to cool dairy cows, and have proven advantageous in dry climates. They work by cooling the air around the cows. The disadvantage is the mist can be easily blown away under windy conditions or when used with fans. If a mist or fog builds up on the cow's hair, it can trap a layer of air between the skin and the water, which holds in body heat. Respiratory problems can also arise if proper ventilation is not provided. In addition, mist and fogging nozzles usually must be operated at high pressures and require regular maintenance, especially when poor water quality conditions exist.
In comparison, soaker nozzles produce a coarse droplet spray, which penetrates the hair and wets the cow's hide. To avoid formation of a mist, the soaker nozzles operate at reduced water pressure of 10 to 15 psi. |