2. Do not operate the fan during rain, fog, or snow to minimize blowing moisture into the bin. Bin vents may frost or ice over if fans are operated when the outdoor air temperature is near or below freezing, which may damage the bin roof. Open or unlatch the fill or access cover during fan operation to serve as a pressure relief valve. Cover the aeration fan when the fan is not operating to prevent pests and moisture from entering the bin and warm wind from heating the grain.
3. Collect some grain samples and check the moisture content to ensure it is at the desired level. However, many grain moisture meters are not accurate at grain temperatures below about 40° F. When the grain is cold, it should be placed in a sealed container, such as a plastic bag, and warmed to room temperature before checking the moisture content.
At temperatures above 40°F the meter reading must be adjusted based on the grain temperature unless the meter measures the grain temperature and automatically adjusts the reading. Check the operator's manual for the meter to determine correct procedures to obtain an accurate value.
4. Natural air drying is not efficient until the average outdoor temperature reaches about 40°F. The moisture-holding capacity and, therefore the drying capacity, of colder air is so limited that drying at colder temperatures is extremely slow and expensive. When natural air drying, adding supplemental heat primarily reduces the final moisture content of the grain and only slightly reduces drying time. Regardless, try to keep the temperature of the grain within 10° of the average outside air temperature to limit condensation in the bin.
Source: weathercentral