A North wall insulated greenhouse dryer was designed, fabricated and tested in no-load conditions under natural convection mode. Experiments were carried out in two different cases namely-Case-I and Case-II. Case-I was north wall insulated greenhouse dryer with solar air heating collector at ground and Case-II is north wall insulated greenhouse dryer without solar air heating collector. Convective heat transfer coefficient, coefficient of diffusivity, heat loss factor, heat utilisation factor and coefficient of performance were evaluated and analysed as performance indicators for newly developed system. The maximum value of coefficient of performance for Case-I was 0.9 whereas 0.86 for case-II. The highest heat utilisation factor was 0.68 for Case-I while 0.61 for Case-II. The maximum temperature difference between inside room air and ambient air for the north wall insulated greenhouse dryer with the solar collector was 30 C, 28 C and 18 C for day 1, day 2 and day 3, respectively. The inside room air temperature is 46%, 42% and 32% higher than the ambient air temperature during day 1, day 2 and day 3, respectively. The results validate the modifications, hence developed system is recommended for fruit/vegetable drying. (C) 2016 Elsevier Ltd. All rights reserved.