| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that it is difficult to efficiently raise the temperature in an area near crops, in an energy-saving manner.SOLUTION: In a frost prevention/freezing prevention apparatus, a fan provided at a high position of a pillar blows warm air from a high place to a low place, and a fan provided at a low position of the pillar blows air in the substantially horizontal direction. On a firm field, a heater is provided. The fan provided at the high position is operated only when the temperature in the high place where an inversion layer can be generated is higher than the temperature in an area near crops, and then when the temperature in the area near the crops drops, the heater is operated. In contrast, when the temperature in the high place where an inversion layer can be generated is lower than the temperature in the area near the crops, the fan provided at the high position is not operated and the heater and/or the fan provided at the low position are operated to blow warm air in the substantially horizontal direction in order to prevent frost damage. |
