Higher airflows allow operators to get the job done faster and therefore do not require as much attention. Likewise, an airflow of 0.5 cfm/bu requires only 20 percent as much time to change the temperature as 0.1 cfm/bu.Īlthough stored grain can and is being aerated with airflow rates as low as 0.03 to 0.02 cfm/bu in commercial storages, a minimum of 0.1 cfm/bu is recommended for on-farm grain storages because it’s an easily attainable airflow level. An airflow of 0.05 cfm/bu takes twice as long as 0.1 cfm/bu to change the bin’s temperature. The required fan time is proportional to the airflow rate. The temperature change occurs as a cooling or warming front moves through the grain and is not done until the front completely passes through the bin. This can happen when using high airflows for extended periods beyond what’s necessary for changing the grain temperature.īecause the purpose of aeration is temperature control, the required air quantity depends on the desired rate of temperature change.Īn airflow rate of 0.1 cubic feet of air per minute per bushel of grain (cfm/bu) will change the temperature of a bin after operating the fan for 100 to 200 hours. However, moisture content can significantly change if substantially more air moves through the grain than is required for a temperature change. Little moisture change results from the drying or rewetting capacity of the small amounts of air necessary for changing the grain temperature. Each 10-degree drop in grain temperature will reduce grain moisture content by about 1/4 percent. The heat removed during cooling leads to some drying. Some changes in grain moisture content occur as a result of aeration.
Aeration is not a grain-drying system do not consider it as such. Increase the moisture content to 14 percent and gain experience in storage management, then gradually work up to the desired level.Īeration changes the temperature of stored grain in response to seasonal temperature changes and maintains uniform temperatures throughout the storage.
If you have been successfully storing corn at 13 percent, do not attempt to increase to 15.5 percent in one step. On the other hand, you can store grain at higher moisture contents with exceptionally good management. These moisture contents may be too high if the grain is poorly managed in storage. *Short-term means until the following June.
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