Nufarmer November / December 2017 NUF NOV.DEC 17 | Page 15

Nufarmer Africa
Chicken production – Setting up a cooling
system for broilers
T
he ability to cool broilers has the advantage that
more chickens can generally be kept in such a
cooled house than in a house without a cooling sys-
tem. In addition, losses as a result of excessive heat in
chickens can be avoided. The area in which the farm
is situated will determine whether it is necessary to
install a cooling system.
Houses with fans should always have cool-
ing systems. Chickens prefer a slow air fl ow. A cooling
system will cool the house without the fan speed be-
ing increased very much. If the outside temperature is
high, it is not possible to cool a house eff ectively sim-
ply by bringing the hot air into the house.
•
•
Cooling can be achieved in the following ways:
• Roof sprays. If no system has been installed and it
becomes really hot, the roof of the house can be
sprayed with water to cool off the house. Some-
times, sprays care placed on the roof permanently.
With this method it is advisable to have gutters to
catch the runoff before it runs from the roof. Cases
have been recorded where the water fl owing off
the roof increased the moisture inside the house
to such an extent that it in fact worsened the eff ect
of the heat.
• Wet pads. Wet pads are commercial structures that
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are placed on one side of the house so that all in-
coming air has to move through them. Fans on the
other side of the house then pull the air through
the wet pads. If the temperature is low, air is simply
pulled through the dry wet pad. If the tempera-
ture rises a few degrees above the recommended
temperature, water is pumped through the pads
and the air moving through them is cooled by the
principle of evaporative cooling. The fl ow of water
through the pads is thermostatically controlled
with an electric pump.
High-pressure micro-sprays
With special spray heads and high pressure (above
2 000 kPa) water is changed from its liquid form
into water vapour. This system also requires some
air fl ow. There is a danger that if there is no air fl ow
and the moisture in the environment is already
high, deaths may be increased; high humidity plus
a high temperature is more dangerous than simply
a high temperature. The system can be placed in-
side the house or in the conditioning area. The sys-
tem can also be used in open houses provided that
there is air movement. An advantage of this system
over low-pressure systems is that the chickens and
equipment do not get wet. The system requires a
high-pressure pump to get the pressure up and
•
good fi ltering and decalcifi cation systems to keep
the fi ne spray heads in good working order.
Low-pressure micro-sprays. This system works at
pressures above 200 kPa. The danger of high hu-
midity and high temperature exists, as mentioned
above. These systems generally wet the chickens
and the equipment slightly. The eff ect of this on
the chickens is that the slight air movement over
them leads to evaporation cooling from their bod-
ies. Filter systems will help the system to function
more effi ciently, but are less critical than with the
high-pressure system. This system can also be
placed in the pre-conditioning area.
Source: Chicken Production: Broilers. By Dr Jean A
Cilliers
WORLDSTAR
FOR PACKAGING
Nufarmer Africa | November/December 2017
15