Cooling Low-moisture Corn in Bins
Nebraska Extension educators have been receiving questions about low-moisture corn ranging from 8-13% and whether cooling the grain would also reduce moisture when air is run in the bin. Dr. Ken Hellevang, North Dakota State University Extension agricultural engineer, helps address these concerns in the following Q&A.
Q: Should low-moisture corn be cooled in bins? Will running air remove much more moisture?
A: The temperature of the corn will change many times faster than any moisture content change. We can estimate the cooling time by dividing 150 by the airflow rate. So, if the airflow rate is 1.0 cfm/bu, it will only take about 15 hours to cool the corn. To change the moisture content of all the corn at that airflow rate will take about 40 days. Even at a typical aeration airflow rate of about 0.2 cfm/bu, it only takes about three days to cool the corn.
Anytime we cool the corn, there will be a minor (fraction of a percent) reduction in moisture. Therefore, with dry corn, running the fan at night during higher humidity conditions is beneficial. I would run the fan all day and night for the most rapid cooling, and just at night if willing to be controlling the fans.
I encourage farmers to cool the corn whenever outside temperatures are 10-15 degrees cooler than the corn, so they certainly could utilize the cooler air to cool the corn.
With the corn at moisture contents of 13% or less, it will store at the warmer temperatures for a while, so there is not a problem with waiting. They will need to cool the corn for winter storage at some time to limit the potential for moisture migration and wet corn at the top of the bin. This occurs if there is consistently at least a 20-degree difference between outdoor air temperature and the corn temperature.