What is the best type aeration for insect control in steel bins, silos & warehouses?
Most insect populations start in the top 3 feet of grain in steel grain bins and warehouses, and the top 4-6 feet of silos. Suction aeration provides much faster cooling of top grain than pressure aeration. Suction cooling also uses the full cooling potential of ambient air as there is no mechanical heat of compression with suction cooling. At 0.1 cfm/bu (standard commercial aeration rate for steel bins), during late summer and early fall cooling, it takes about 100-120 hours of fan operation to cool all the grain throughout a stored grain mass, regardless of size, shape or depth. In 10,000 bu to 100,000 bu steel bins with rounded (not peaked) grain surfaces, using 0.1 cfm/bu airflow, the top 3 feet (10-15%) of steel bin grain can be cooled to average ambient air temperature in the first 20-25 hours of fan operation. That may be done during 5-7 nights of fan operation from 2 AM to 7AM using a timer to start and stop the aeration fans, based on predicted TV or internet weather. In 20,00
