We developed novel dry-air-generator systems for drying wheat from May to June in Saga because the environment is highly humid and atmospheric air cannot be used. The first system generates low-humidity air by utilizing heater power that is saved by controlling a fan in an inverter. In the second system, a part of the airflow refl ux is allowed to flow through a pipe for generating low-humidity air. Compared with conventional systems, although our systems have a far lower air volume ratio, they exhibit higher drying speeds. Therefore, they show potential for achieving high energy efficiency. Temperature and humidity measurements under the floor and at the top of the silo confirmed the efficiency of these systems.