In today’s modern solid sidewall houses, it is essential to provide some level of minimal ventilation during down time to prevent houses from sweating. If condensation is allowed to form inside the house, it will mix with ammonia gas from the litter and the resulting liquid ammonia is highly corrosive to equipment. This is the main reason that corrosion occurs along the tops of inlet and feedline cables. It is also very important to ventilate when workers are present inside the house to remove the accumulated ammonia. One should never attempt to work inside an empty chicken house without ventilation. Because the ammonia concentration in the air will get quite high, open all vent boxes and run enough fans to clear the ammonia to levels safe for workers when working the litter and performing routine maintenance during layout. Afterwards, shut the house back up and revert back to the minimum ventilation schedule to continue with the litter curing process.
Based on experience with thousands of commercial poultry houses, it is recommended that the house be shut tightly as soon as the last birds are removed from that house. Do not wait for the entire farm to be caught before closing the house up tightly. The purpose of closing the house is to begin the litter curing process as quickly as possible. The litter is at its highest temperature as soon as the birds leave and closing the house up immediately harnesses that heat to begin the litter curing. If one waits until the entire farm is caught, much of that free heat in the litter will be lost and the litter curing process will be delayed. The house should remain closed until the chicks arrive except for times when the house is being actively worked in.
Strategies for a minimum ventilation program during the layout will depend on the litter quality factors mentioned previously, de-caking/conditioning method, time of year, type of housing and equipment, and duration of layout. The most common strategy is to ventilate just enough to prevent the house from sweating. Experience shows that this retains litter temperature for a longer period of time resulting in greater ammonia release from the litter. Running fans continuously drops litter temperature and forms a dry skin on the litter surface preventing the litter form curing properly. Fans and/or attic inlets should only be run during the hottest parts of the day when the outside air mass is at its driest to prevent drawing moisture into the house. A more aggressive ventilation schedule may be required when the litter and cake have been pulverized or windrowed between flocks due to much higher levels of ammonia release and the added moisture from the cake left in the house.
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