Hot weather management
Evaporative cooling systems cool the air by evaporating water. These systems can be effective to reduce temperatures, but be aware that they will add humidity into the air. If the humidity is too high, birds will pant and experience stress as they try to cool down. For this reason you should not use evaporative cooling when the Rh (relative humidity) is >80%. The drier the air at the time of using the evaporative cooling, the more evaporation can occur, and the greater the cooling effect.
Evaporative cooling can be used when outside air is more than 87˚F (31˚C) and humidity is less than 75%. The graph below shows how how humidity (represented by the blue line) changes as the temperature (represented by the red line) rises.
Czarick, 2008
Cool cells
Cool cells can produce up to 20˚F (11˚C) of cooling. If you are in a region that regularly reaches high temperatures in the summer, cool cells will be worth the investment to keep your birds comfortable.
Using imperial measures, the example below is a situation where the temperature in the barn is 105°F. The air speed of the fans provide 15°F of wind chill cooling. In combination with the cool cells, which provide 20°F of cooling, you can see how 105°F has been cooled to 70°F, which puts the barn in the correct comfort zone.
Foggers
Foggers can produce up to 12˚F of cooling. If you are in a region that reaches high temperatures less frequently, foggers can be effective at keeping your birds comfortable.
In a similar example as the one above, with the air speed providing 15°F of cooling and foggers providing 12°F of cooling, 95°F is modified to 68°F.