Greenhouse heating requirements for high-value vegetable crops under winter conditions: a case study of Ludhiana, Punjab, India
摘要
A study was undertaken to determine the greenhouse heating requirements for growing different high-value crops (cucumber, tomato, and pepper) during winter climatic conditions. The investigation was conducted at Punjab Agricultural University, Ludhiana. The long-term climatic data were obtained from the meteorological observatory of PAU, Ludhiana.Heat loss components were estimated using steady-state energy balance equations for conduction, infiltration, and perimeter losses. The statistical analysis was performed using XLSTAT software. The heating requirements were highest for cucumber and lowest for tomato, mainly due to their respective design temperature requirements under the same minimum outside temperature. The average monthly heating requirements for cucumbers, peppers, and tomatoes were 19.1, 12.8, and 15.6 kWh, respectively, while their total seasonal heating requirements were 76.5, 51.2, and 46.9 kWh, respectively. Across all crops, the heating demand was highest in January and lowest in November. The heat loss from the greenhouse was dominated by conduction (50.7–81.6 kWh), while perimeter heat losses were comparatively minor (2.1–3.3 kWh). These findings highlight that both crop selection and reduction of conductive heat losses are key factors in improving greenhouse energy efficiency. Practically, optimizing crop choice and enhancing insulation can help reduce heating demand and support sustainable greenhouse production.
Graphical Abstract