This research introduces and validates a finite‐element (FE) model for drying tomato flakes in a passive greenhouse dryer, supported by experimental data. The simulations accurately monitor crop and ground temperatures, reaching 49.1 and 61.1 °C, respectively. The moisture reduction is 96–4.25% (Wb), with a minimum relative humidity of 28.40% and a drying efficiency of 50.30%. Energy and exergy efficiencies are evaluated at 80% and 52.82%, respectively. The embodied energy is 1209.56 kWh, and the total cost of the proposed system is 15433.50 INR. The FE model effectively monitors temperatures and achieves a remarkable reduction in moisture, demonstrating its potential to optimize greenhouse dryer and promote sustainable, cost‐effective drying practices in the food industry. The rigorous comparison between experimental and simulated results confirms the precision of the FE model, highlighting its potential in optimizing greenhouse dryers and promoting sustainable, cost‐effective drying practices in the food industry.