It is a common practice to use vertical ventilation to cool down the chickens in the hot summer season. For high-density intensive egg farming, the wind speed in the chicken coop should reach at least 3m/s, and the wind speed in the chicken house in high-temperature and high-humidity areas should reach more than 4m/s in order to get a better “wind cooling effect”.
The “wind-cooling effect” mainly refers to the wind speed to reduce the body temperature of chickens.
How much effect can wind speed have on the body temperature of chickens?
“According to a study by the University of Georgia, the wind speed increased from 0m/s to 2.54m/s. The body temperature of chickens will drop by more than 6°C.”
In order to obtain greater wind speed, I am the usual practice is to make the chicken house ceiling, reduce the height of the chicken coop, or from the top of the chicken coop along the triangular roof vertically down every certain distance to install a windbreak or windbreak curtain to reduce the cross-sectional area of the chicken coop to improve the wind speed in the coop.
Why do this, mainly because the wind speed is closely related to the cross-sectional area of the chicken coop.
Calculation of wind speed in a longitudinally ventilated chicken coop: wind speed = ventilation volume / cross-sectional area of the coop
It is clear from this formula that to increase the wind speed of the coop, either increase the ventilation of the coop, i.e. increase the number of negative pressure resistant fans, or reduce the cross-sectional area of the coop.
Increasing fans means increasing costs, increasing electricity consumption, increasing maintenance costs, and in the long run adding significant operating costs to the enterprise.
Then increase the wind speed should be considered from reducing the cross-sectional area of the chicken coop. Below we understand the changes of the chicken coop before and after increasing the wind-blocking curtain by specific calculations.
For example: a chicken coop 12m wide, 100m long, the side walls of the coop are 2.4m high, the middle of the coop (the highest) is 4.8m, the coop is installed with 10 50 inch fans, the ventilation capacity of each fan at -50 Pa is 31000m³/h.
Then the wind speed of the chicken coop should be: wind speed = ventilation volume / cross-sectional area = 31000 / 3600 × 10 / [12 × (4.8 + 2.4) / 2] = 86.1/43.2 = 1.99m / s
If we install the ceiling or wind curtain in the chicken coop, so that the height of the top of the coop or the lower edge of the drape from the ground is 3.6m, and the height of both sides of the coop remains unchanged, the wind speed is = 31000/3600×10/[12×(3.6+2.4)/2]=86.1/36=2.39m/s
Therefore, in the case of the same number of fans, by reducing the cross-sectional area of the poultry house can increase the wind speed on the basis of the original 0.4m/s, that is, the efficiency increased by 20%, the wind speed changes produced by the wind cooling effect is also different, the difference between the two wind cooling effect corresponding to the temperature of about 2 ℃, in the case of extreme high temperature, the temperature difference of 2 ℃ is enough to cause serious harm to the chickens.
Post time: Aug-12-2022
