Temperature control method of heat source water for heating in greenhouse for horticulture

摘要

PROBLEM TO BE SOLVED: To prevent the occurrence of damage to a crop in a green house in correspondence to lowering of the room temperature of the green house when a heating load is increased due to rapid lowering of an outside air temperature due to the rapid change of weather or abnormal weather during programmed energy saving operation of a heater using heat source water for heating a green house developed by an applicant. SOLUTION: A room temperature and an outside air temperature are always monitored. When heating is effected through energy saving operation, in the case a room temperature is decreased, energy saving operation is released and in the case an outside air temperature is reduced to temperature not higher than a predicted lowermost outside air temperature, an instruction to release normal water temperature control and effect safety control is transmitted to a three-way valve control part for the heater to regulate a heat source water temperature so as to switch to the highest capacity heating.