Most aeration fans are sized to produce a minimum airflow rate of 0.1 m3/min/t (0.1 cfm/bu) in on-farm grain storage structures. At this airflow rate a significant amount of time is required to move a cooling front completely through a bin. The desired grain temperature and prevailing weather conditions will have a significant effect on required fan size. Thirty years of weather data were analyzed for the eastern United States to determine the amount of time available in temperature windows between 0 to 15.C and 0 to 17.C. Contour maps were generated with ArcMap 8.3 for the percentage of each month within the given temperature windows. A substantial amount of time (over 4% of the month) is available within temperature limits of 0 and 17.C between September and April. This indicates that airflow rates of at least 0.6 m3/min/t (0.5 cfm/bu) would be more adequate to completely move an aeration front through a bin for summer harvested grain in Southern regions of the United States. However, during July and August only the northern half of the United States would have a sufficient amount of time available for cooling grain below 17.C using an airflow rate of 0.1 m3/min/t (0.1 cfm/bu). The maps generated provide a starting point for sizing aeration fans in the eastern United States.

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Published in Applied Engineering in Agriculture, v. 20, issue 5, p. 665-669.

© 2004 American Society of Agricultural Engineers

The copyright holder has granted the permission for posting the article here.

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