DRYCOOLER: new cooling system

For over twenty years, the GRIMAUD FRERES SELECTION hatcheries were equipped with evaporative cooling towers.

This water cooling system for the incubators and hatchers works through evaporation (adiabatic process). It is a very natural, energy-saving system but it was not enough during heat waves and needed to be compensated with the use of the water network without recycling (“lost water system”). . Since 13 December 2004, a new regulation concerning the risk of Legionnaires’ disease has required recurrent analyses and systematic bactericide treatments of the water in the towers. These new constraints resulted in significant costs which could be as much as €6,000 per tower a year or €12,000 per hatchery, not including the time spent by people in charge of monitoring them. Despite all the precautions taken, it is very difficult to maintain the level of contamination below the regulatory threshold across our hatcheries (linked to managing the restarting of the machines). Each exceedance, even slight, forced us to stop the tower and fully clean it. During these periods, we worked with “lost water” to cool the machines. Beyond a certain threshold, we had to make a declaration to the French Departmental Direction for the Protection of Populations, or organise a check by an independent body. In view of this, the General Services accompanied by the environment service tested a solution to eliminate the Legionnaires’ disease constraint. Rather than opting for a very energy-intensive system for producing iced water, the choice was guided towards an air cooling system but in a closed circuit called a “DRYCOOLER.” Paired with a little cold group to cope with extreme heat peaks, this system currently equips the GRIMAUD FRERES SELECTION hatcheries. For example, the installation cost for hatchery C7 was €46,000. Thanks to this system, we have detached ourselves from the heavy regulatory constraints whilst opting for installations with a low impact on the environment and with lower running costs.