The Problem: The largest cause of spoilage in grain is moisture migration. This occurs when the grain temperature is different from the average outside temperature. Keeping grain near the average outside temperature prevents moisture migration.(https://tgmsystem.com/sentry-pac/)
The moisture content (”MC”) in grain after harvest impacts storability, usefulness and value. Over dry grain weighs less, is more brittle and is less palatable. In general a higher moisture content increases usefulness but too high increases risk of mold growth and insect activity. There is a narrow band of MC that delivers maximum returns. (https://tgmsystem.com/sentry-pac/)
What makes Sentry PAC different from the other aeration controllers on the market?
It's the only proactive machine available. It actually samples the temperature and humidity every 15 mins creating a 21 day average. This system makes the system run the fans at a wider parameter or a narrow parameter based on what moisture you want the grain to be stored at. For example, if the desired moisture is 15.5, the TGM will continually widen and narrow the parameters depending upon the weather to maintain that desired moisture number.
No other programmed aeration controller can do this.
No other system is proactive.
They all rely on bin temperatures in order to get the right temperature on your grain. They are all retroactive to a problem that is already existing.
How does the PAC operate?
The PAC uses a running 21 day average temperature as a targeted temperature. The high and low ends are limited to keep grain cooler in summer and to not get colder than necessary in winter. The relative humidity (RH) of the outside air is included in the decision so MC can be regulated at the same time.
A temperature band (+/- range) around the targeted temperature and a moisture band around the Targeted Moisture Content (TMC) are established. It checks every fifteen minutes to see if the temperature is within the band. If it is, it checks to see if RH will produce this TMC. If it will, the fans are turned on. This repeats every fifteen minutes so the fans will continue to run until conditions change or the backlog hours go to 0.
The bands are increased or decreased automatically by the size of the backlog of unused run hours. Each midnight the budgeted run time is added to the backlog. Fan runtime is subtracted as it accumulates. If no run time occurs for awhile, the bands are widened to make fan operation more likely. After running the bands are narrowed to become "fussier". This action is somewhat like a governor, always picking the best air available — optimizing for you even while you sleep. (https://tgmsystem.com/sentry-pac/)