Extra Cooling can be provided by, for example, fitting a foggingsystem to the fans. A separate foggingsystem only works in combination with fans, whereby measures should be taken to prevent extreme humidity. A ring of high-preasure (70bar) spraying nozzles can be mounted to the fan, with a time clock or special regulator ensuring regular water atomisation. The very fine droplets evaporate quickly, lowering the air temperature by some 3 to 4 degrees.
This can also be placed in the outside wall to draw outside air into the barn through cooling panels. This method, the so-called tunnel ventilation system, can realise temperature reductions of as much as 8 to 12 degrees.
A good cooling system produces an air velocity at animal height of at least 2.5-3.0 m/sec throughout the barn. While the temperature of the air does not drop, the wind chill at this air velocity means the animals experience a temperature that is 2 to 4 degrees lower.
The close-up group and fresh milking cows are the most important target groups for a cooling system.