DESIGN CONSTRUCTION AND PERFORMANCE EVALUATION OF INDIGENOUS HEATING SYSTEM FOR HYDROPONICS GREENHOUSES

Abstract

Hydroponic farming enables year-round vegetable production, however, it requires specific temperature and humidity control for optimal plant growth. In winter, when ambient temperatures drop below 16 °C, supplemental heating becomes essential. To address this challenge, an indigenous air-heating system was developed and evaluated for its effectiveness in three greenhouse types including glasshouse, fiberglass house and polythene house. Three types of fuels (wood, crop residues and solid waste) were used during experimentation. Wood shown better performance for heating of greenhouse as compared to its competitors (crop waste, solid waste) because of its higher calorific value. However, crop waste and solid waste fuels were more economical as well as abundantly available. Results showed that the glasshouse provided the most effective temperature regulation due to its higher heat transfer efficiency under higher temperature gradients. The fiberglass house demonstrated moderate performance with an average heat output of 26,000 Btu, while the polythene house was least effective, producing only 18,000 Btu with poor heat distribution. Inadequate heating in the polythene house delayed plant growth and fruit ripening. Overall, the study highlights the importance of greenhouse design in achieving efficient heating for hydroponic crop production under cold climatic conditions.