Batch machines are well suited to drying small quantities of grain. A continuous-flow machine dries moist grain whilst it flows from the inlet to the outlet. In a continuous-flow system, air temperatures are generally higher, as heating is applied more uniformly, for a shorter period of time and to a thinner layer of grain. Continuous-flow machines are generally more efficient if drying large quantities of the same type of grain and have a lower requirement for labour. Both batch and continuous-flow driers come in stationary or portable varieties.
Portability usually means that the machine is more versatile and easier to re-sell.
Portable driers are often used in the paddock along side the header and delivery trucks. Stationary driers are best used as a part of a well-established grain storage and handling system. They need to be associated with a moist-grain holding silo and a conveyor system. Heating source Availability, cost and maintenance are the usual factors in selecting a fuel type for heating the drying air. On the south coast of Western Australia, the most common energy sources are LPG and diesel fuel.