반밀폐형 온실 내 온·습도 환경의 시·공간적 변동 분석

초록

Semi-closed greenhouses are designed to control temperature and humidity independently of outdoor weather, but few studies have analyzed the temporal variation and spatial distribution of the indoor environment over an entire cropping season in the semi-closed greenhouse. In this study, outdoor weather, indoor air temperature and humidity, and leaf temperature were measured over one cropping season in a semi-closed greenhouse to quantify the temporal variation and spatial uniformity of its environmental control performance and to relate them to tomato productivity. Ten-minute records were classified by day and night and by season, and monthly variables were correlated with yield per unit area. The standard deviation of indoor air temperature was 52% of that outdoors, indicating effective buffering of outdoor fluctuations. However, the mean daily temperature range indoors (11.6°C) exceeded that outdoors (9.5°C), suggesting that daytime solar heat gain was not sufficiently removed. High humidity persisted year-round: relative humidity ≥ 85% occurred in 97.2% of nighttime records, and monthly means ranged from 83.8% to 87.5%. In winter, leaf temperature was below air temperature for up to 84.1% of nighttime records, suggesting a potential risk of leaf condensation if leaf temperature locally falls below the dew point. The maximum–minimum temperature difference among three points averaged 1.08°C overall but 2.13°C on winter nights, when 55.2% of records exceeded 2°C. Total tomato yield was 37.39 kg·m-2, with 36.1% from the three winter months; the non-marketable fruit ratio (5.0% overall) was positively correlated with monthly mean indoor temperature (r = 0.820, p = 0.007), and the monthly day–night temperature difference showed the highest correlation with yield per unit area (r = 0.684, p = 0.042). Future studies should address dehumidification and heating to reduce nighttime humidity and condensation risk, duct layout to improve winter air distribution, and multi-season verification.

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