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EQM Control Model
EQM Conditioning Principles
These principles are important to understand because it affects how grain is dried, the Drying Front, and
Equilibrium Moisture (EQM).
When water is turned to vapor it takes energy away from the surface of what it is leaving. This is just like when
people sweat.
These principles are important to understand because it affects how grain is dried, the Drying Front, and
Equilibrium Moisture (EQM).
3.
Temperature and Humidity Principles
Temperature affects the ability of air to carry water. As the temperature rises, it can hold more water. When the
temperature drops, it can start condensing. The maximum amount air can hold at a given temperature is said to be
100% Relative Humidity, so if air is carrying half of the maximum amount it would be 50% Relative Humidity.
When water is turned to vapor it takes energy away from the surface of what it is leaving. This is just like when
people sweat.
These principles are important to understand because it affects how grain is dried, the Drying Front, and
Equilibrium Moisture (EQM).
4.
Equilibrium moisture
Equilibrium Moisture is a pressure balance between the water vapor in the air and the water in the grain.
EQM is the temperature and humidity combination needed to bring or keep grain at a specific moisture.
Aeration with Target EQM air will drive grain to that moisture.
If ambient air is too wet, a small amount of heat can usually bring it to the Target EQM.
If ambient air is too dry, cooling would be required to bring it to the Target EQM.
Temperature and Relative Humidity of the air determine the pressure of the water in the air trying to push water
into the grain.
Grain type and its moisture content determine the available pressure from the water in the grain to push against
the air.
