Vic Ventilation

Winter is once again at our doorsteps. Did you prepare your Poultry house?

That’s right! There’s no getting around it. Winter is once again at our doorsteps. This document will remind you how to prepare your poultry house for the cold season.

1. Adjust air inlets: It is very important that you check your air inlet openings in the fall. When it starts opening, a well-adjusted air inlet is open about 1/8 inch over the entire length of the poultry house (a thin, uniform stream of air over the entire length of the building). A poor adjustment will produce temperature differences along the length of the building and cause discomfort to the birds. When air inlets are open too wide in one section, the temperature is colder than the house average and this greatly increases heating bills in cold, windy weather. On the other hand, air quality (relative humidity and ammonia) is poor in a section where air inlets are not sufficiently open.

2. Check weatherstripping on outside doors and window panes: Weatherstripping in a poultry house is very important for several reasons. First of all, a tightly sealed poultry house will have fewer cold spots in rearing pens and will ensure that fresh air enters where it should, that is through air inlets. It is also almost impossible to maintain adequate static pressure (vacuum) in winter in a poorly sealed poultry house. In addition, air infiltrations will greatly affect heating bills. In cold and windy weather, the rate of air infiltration can easily reach up to 4 air changes per hour in a poorly sealed poultry house. This represents a ventilation rate of about 0.43 CFM (cubic feet per minute) per bird. If you consider that minimum ventilation needs are less than 0.1 CFM per bird during the first week of rearing, you’ll understand how important it is to adequately seal your poultry house, not to mention that heat losses amount to 60 to 85% of heating bills, depending on bird age.

3. Winterize your summer fans: Summer fans should be winterized during the cold season to minimize possible air infiltrations. On fans where the shutter frame is on the inside, use insulated shutters and apply weatherstripping on the outside frame. For fans with outdoor shutters, insulate the fan with mineral wool.

4. Outdoor air inlets: In order to reduce wind action on air inlets, several producers have installed outdoor air inlets at the base of their wind shelter. These inlets are activated using a manual winch and replace the geomembrane fastened to the base of the wind shelter. This not only allows you to better control static pressure (vacuum) in your poultry house but also reduces heating costs in very windy weather.

5. Reprogram automatic air inlets: We strongly recommend you reprogram or at least validate automatic air inlet programs for the coming winter. They may have become misadjusted during the warm season for any number of reasons. In addition, loose pulleys or stretched cables in the air inlet suspension system can cause small errors in programmed air inlet openings, slight as they may be.

6. Readjust offsets/bandwidths – electronic controllers: It is common practice to readjust certain parameters on your electronic controllers when winter arrives, in order to slow down fan speeds and reduce drafts in the poultry house. The bandwidth (the number of degrees over which the fan goes from minimum speed to full speed) for stages 1 and 2 is often increased in cold weather while the heating offset is often decreased to maintain room temperature near the set point.

7. Maintain your humidity sensor: For those who have humidity sensors in their building, these units require some maintenance. Most manufacturers recommend replacing the filter that covers the humidity sensor every 6 months. The humidity sensor, for its part, should be replaced every 2 years. You may be interested to know that these sensors automatically increase the fan speed on the first stage when the humidity level in the building is too high. This helps improve air and litter quality in the poultry house while reducing heating costs.

8. Check heaters: Most heating units commonly used in poultry houses require some maintenance. Please consult a specialist for these matters.

9. Verify ceiling insulation: It is important that you occasionally verify the ceiling insulation in your poultry house, especially if you noticed some condensation (humidity) on the ceiling last winter. The recommended insulating value for poultry house ceilings is R40.

10. Attic ventilation: If you are in the attic, you should also verify the ventilation capacity of the roof space. The recommended capacity for an agricultural building calls for a 4 sq. ft. opening at the rooftop for every 1000 sq. ft. of ceiling. Attic ventilation removes excess heat in the summer.

Let’s hope the winter ahead won’t be too harsh…

Bruno Marquis
Thevco Electronics Inc.