Ventilation of Agricultural Buildings

Since the start of Galebreaker Agri in 1984 we have understood the importance of getting fresh air into agricultural buildings. Through innovation and product design we aim to continually improve the air quality in agricultural buildings, reduce heat on livestock and reduce respiratory diseases and sickness which help to produce better yields and improve livestock performances. Improving air quality can only be reached by exchanging the existing air in the agricultural building. Research has shown that in summer periods up to 22 to 45 times the air volume of a dairy barn needs to be exchanged with fresh outside air.

To achieve such a high level of air exchange, natural ventilation plays a major role and as ventilation specialists, we need to understand the concepts of barn design, the principles of air in-and-outlets and the essence of animal welfare.

Air Volumes

To achieve this air exchange one needs to understand the air volume needed per animal category and animal age.

Recommended air volume for natural ventilated barns:

  • Dairy cattle roughly 6-7 m³/100 kg of body weight
  • Pigs roughly 3,5 m³/meat pig
  • Dairy goats roughly 5-6 m³/animal



Theoretical In-and-Outlet Rules for Dairy Barns

  • Inlet height roughly 0,4-1,0 m²/animal for summerly conditions
  • Outlet width roughly 1,5 cm per m/barn width

Animal Welfare

A badly or insufficiently ventilated agricultural building will lead to poor air quality; the air will be full of moisture, bacteria, viruses and the smells of ammonia. This will ultimately lead to a decrease in yields and higher costs for animal welfare.

Next to poor air quality, heat stress on animals can lead to losses and severe health issues. The body temperature for dairy cattle needs to be around 38°C (+/- 0.5°C) and needs to remain constant. As soon as the thermal exchange to the environment is not sufficient, the animals will go into the different phases of heat stress symptoms. The comfort zone for milking cows lies between 4-16°C and when the temperature and humidity goes up (THI index), the animal will start to reduce her feed intake by 10-30% and this can lead to a milk production drop of as much as 20%. When the animal reaches a critical point, her overall health status and fertility is affected dramatically.

What kind of measurements can be done to reduce/prevent heat stress?

Air exchange rate in the building needs to be increased by optimized natural ventilation

Fresh water needs to be provided

Changing feeding times

Create shade areas

Clean and fresh cubicles
Increase chill effect on animals

Create A Chill Effect On Animals

When the natural ventilation principles have been optimized but heat stress still occurs to the herd, mechanical ventilation can be used to chill the animals by blowing air with an increased air speed over the animals. By increasing the air speed around the animals up to 1.8 m/sec 1.60 meters from the floor, the chill effect will have a positive effect on cooling the animals and reducing heat stress symptoms. Galebreaker can provide you with a wide range of mechanical ventilation products to suit a range of requirements.

Chill Effect: Temperature as felt by a cow with different airspeeds
Temperature °CRelative
Humidity %
Temp./air speed, m/sec.

Source: R. Barnwell Pittsburg 2002

Weather Protection

The changing climate has an influence on the barn building and its content which needs to be protected in the best possible way. Galebreaker specialize in using fabrics that can withstand high wind speeds and also reduce the air speed entering a building when required. In addition to using fabrics to protect a building and its contents, Galebreaker can also supply automated systems that react to weather conditions such as rain, wind speed, wind direction and temperature.


The Best of Outdoors Indoors®

Galebreaker Agri is proud to state that we develop and innovate products and solutions that provide The Best of Outdoors Indoors®