It’s time to start thinking about and preparing for cold weather ventilation. Even though minimum / transition ventilation is important year round, it is even more important to get things right during cold weather to assure the welfare of the chicken and control of litter conditions.
It is not as critical when the outside air is warm and the inside air falls to the floor. However, when the outside air begins to get cold and damp, it is very important to keep the air off the floor and directed into the peak of the house. There are a few things that are important to enable you to direct the air into the peak of the house where the air is warm and dry. First, the house should be as air tight as possible. Second, ensure that the incoming air speed or inlet air pressure is adequate to make the air move to the peak of the house. Third, the direction the air enters the house must be clear of all possible restrictions up to the peak.
When repairing air leaks to make the house more air tight, start near the fans and the floor, working from end to end to keep the air off the floor. The air speed entering the house (inlet pressure) must be based on how far you want the air to travel one it enters the house before it drops to the floor and is mixed with the warm air in the top of the house. There are several things that can contribute to low air speed (inlet pressure), such as, too many air leaks, not enough fan capacity, poor fan performance due to loose belts, and dirty blades and / or shutters.
The direction the air enters the house is determined by the type of inlet being used and the position of the inlet blade as the air passes across the inlet. When counterbalanced (weighted) inlets are used they should be sized to match the width of the house and fan capacity necessary to maintain the minimum oxygen demand of the chickens. When used for a combination of minimum and transition ventilation where there should be two different counterbalanced (weighted) inlets used with the transition inlets weighted slightly heavier than the minimum inlets. When mechanical inlets are used the pressure must be set based on the inlet pressure, not house pressure, and only opening and closing based on the change of pressure. The inlets must close the fans go off. The inlets, fans, and fan shutters must be maintained and kept clean at all times to allow for proper operation and accuracy. The correct house inlet pressure must be used based on the width of the house and how far the air is to travel once it enters the house. There should always be an air deflector installed on the outside of the sidewall inlets. The deflector will limit the influence of the wind on the side of the house on inlet pressure and help with inlet freeze ups during extreme cold weather.
To control the litter condition in cold weather, the cold incoming air drafts must be kept off the floor and the house air temperature should be maintained above 55 degrees F, (warmer will help) to allow for evaporation of the moisture in the air (humidity) and keep the birds comfortable and performing.
Air quality and control is the key to good performance and production costs.