하절기 주간 포그 냉방과 야간 히트펌프 냉방이 온실 환경 및 작물에 미치는 영향 분석

This study was conducted to analyze the effect of fog cooling during daytime and heatpump cooling at night in greenhouses in summer. During daytime, the average temp. and RH of the control greenhouse which had shading screen were 32.1°C and 59.4%. and the average temp. and RH of the test greenhouse which had fog cooling were 30.0°C and 74.3%. At this time, the average outside temp. and RH were 31.4°C and 57.7%. So, the temp. of the control was 0.7°C higher than outside temp., but the temp. of the test was 1.4°C lower than outside and 2.1°C lower than control. The average RH was 74.3% in the test and 59.4% in control. The average temp. and RH of the control greenhouse which had natural ventilation at night were 25.2°C and 85.1%, and the average temp. and RH of the test greenhouse which had heat pump cooling were 23.4°C, 82.4%. The average outside temp. and RH at night were 24.4°C and 88.2%. The temp. of the control was 0.8°C higher than outside temp., but the temp. of the test was 1.0°C lower than outside and 1.8°C lower than control. The average RH was 82.4% in test and 85.1% in control greenhouse. There was no significant difference between the plants growth eight weeks after planting. But after the cooling treatment, the values of stem diameter, plant height, chlorophyll in test were higher than control. The total yield was 81.3kg in test, 73.8kg in control, so yield of test was 10.2% higher than control. As a result of economic analysis, 142,166 won in profits occurred in control greenhouse, but 28,727 won in losses occurred in test greenhouse, indicating that cooling treatment was less economical.