A greenhouse works by trapping solar radiation within its structure, creating a warmer environment than the outside surroundings, which benefits plant growth.
Here's a breakdown of the process:
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Sunlight Enters: The transparent glass or plastic roof and walls allow a large amount of visible light to pass through into the greenhouse. This is shortwave radiation.
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Absorption and Re-radiation: This light is then absorbed by the plants, soil, and other objects inside the greenhouse. These objects heat up and re-radiate energy as longwave infrared radiation (heat).
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Trapping Heat: The glass or plastic of the greenhouse is transparent to visible light but not as transparent to infrared radiation. This means that the heat radiated by the objects inside is trapped, preventing it from easily escaping. This is the greenhouse effect.
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Convection Reduction: Greenhouses also reduce convection. Outside, warm air rises and is replaced by cooler air. Inside a greenhouse, the walls block wind, reducing the mixing of inside and outside air.
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Creating a Warmer Environment: Because the heat is trapped and convection is minimized, the temperature inside the greenhouse rises, creating a warmer, more stable environment suitable for plant growth, especially in colder climates or during colder seasons.
In summary, a greenhouse increases the temperature inside by allowing sunlight to enter, absorbing this light and converting it into heat, and then preventing much of that heat from escaping through radiation or convection. This creates a favorable environment for plants to thrive.
