Temperature Sensor/Thermostat Placement in Broiler-Breeder Houses

Tip Category: 
Environmental controllers
Hot weather management

When placing fan temperature sensors/thermostats in broiler-breeder houses it is important to realize that the environment on the slats can be very different than that in the scratch area, especially during hot weather (Figures 1 and 2).  In tunnel ventilation mode, air speeds on the slats are typically half those in the scratch area, which leads to not only a reduced wind-chill effect for those birds on the slats, but lowered air exchange rates as well (Figure 3).  Relatively low air exchange rates, coupled with heat being produced by the birds and side wall curtains, can result in air temperatures on the slats being four to eight degrees higher than those in the scratch area (Figure 4).  If tunnel fan temperature sensors/thermostats are placed in the scratch area the birds on the slats may not receive the cooling they require because tunnel fan operation will be based on a relatively cool location not the hottest, namely the slats.  In a way, placing fan thermostat/sensors in the scratch area is not that different than placing them in front of the evaporative cooling pads.  Though the birds in front of the pads would be comfortable, those at the fan end of the house could get very hot because there would be no thermostats/sensors to sense the conditions near the fans.
To insure that the hens on the slats receive adequate cooling, all or a portion of a houses temperature sensors/thermostats should be located in the vicinity of the outside feed line on the southern side of the house.  Locating temperature sensors/thermostats on the slats will not tend to cause problems during the cooler times of the year because there tends to be less of a temperature difference between the slat and scratch areas of the house.  In houses with environmental controllers, a producer can place half the temperature sensors in the scratch area and half on the slats on the southern side of the house.  During hot weather, the tunnel fans could be operated based on the slat air temperatures on the tunnel fan end of the house (the hottest location in the house).  During more mild times of the year, a producer could opt to operate the fans off an average of slat and scratch area temperature sensors....