Global warming situation has affected many life in the world; especially its effects on agricultural industry. Greenhouse was one of many tools which was brought to help farmers in growing many plants and flowers in uncontrollable environments for long time. This work was aimed to build a low-cost controlled temperature greenhouse prototype. The greenhouse prototype was studied for temperature distributions inside the prototype to sow marigold seedlings. A water evaporative cooling system was

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... osen to remove heat from the greenhouse, a low-cost temperature control set was fabricated to help controlling air flow and temperature inside the greenhouse. A cooling pad system was chosen as the evaporative cooling system in this work. The greenhouse frame was built locally as a length of 2.1 m., a width of 1.8 m. and a height of 3.1 m. and was covered with clear UV reducing plastic. The cooling pad system consisted of 25-watts ventilating fans with a length of 30 cm, a width of 30 cm, a height of 16 cm and one 60-watt water pump. The low-cost temperature control set was connected with the cooling pad system to turn on and off the fan of the system automatically and to remove the humid air out of the greenhouse. Six different seedling materials; pure peat moss, pure bagasse, bagasse mixed with soil at 1:1 and at 1:0.5 by weight, bagasse mixed with soil and rice-straw biochar at 1:1:0.5 and at 1:0.5:0.5 by weight, were also investigated in the greenhouse. The experimental results showed that using one cooling pad could reduce inside temperature with an average temperature different of 2.5 Celsius while using three cooling pads could reduce inside temperature with an average temperature different of 5 Celsius. The air circulation system also affected the temperature distribution inside the greenhouse and could control the temperature inside the prototype. The seedling material which was prepared from bagasse mixed with soil; at a mixing ratio of 1:0.5 by weight, allowed marigold seedling to grow the most in the same experiment period.