Definitions - v


This is usually defined as the act of replacing stale or noxious air with fresh air.

In the eco field it is also important to differentiate between what are termed passive ventilation and active ventilation. Passive ventilation is where no additional electrical or mechanical energy is required to make the ventilation work. Active ventilation on the other hand won't work without using additional energy.

Passive ventilation is an aspect of passive building design and often utilizes heat chimneys and natural air flows across the land to achieve adequate ventilation.

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The process where worms feed slowly on decomposing materials (e.g. vegetable scraps) in a controlled environment to produce nutrient-rich soil.

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Vertical Axis Wind Turbine

A wind generator design where the rotating shaft is perpendicular to the ground, and the cups or blades rotate parallel to the ground.

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Vertical-axis Wind Turbine

A wind turbine with the axis or main shaft mounted vertically, or perpendicular to the earth's surface. This type of turbine does not need to be turned to face the wind - the wind always blows across it. Types include Savonius and Darrius.

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The evolution of a new species from a group separated from the original species by a geographic barrier.

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Rain which fall in the sky but evaporates before it reaches the ground.

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Virgin Materials

Resources extracted from nature in their raw form, such as timber or metal ore.

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Virgin Paper

Virgin paper is paper that contains no recycled content and is made directly from the pulp of trees or, alternatively, cotton.

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Volatile Organic Compounds

Volatile Organic Compounds (VOCs) , are carcinogens found in paint, finishes, synthetic foams, fabrics and stains. Most labels should indicate if something has low or zero VOCs.

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Voltage Drop

The voltage lost along a length of wire or a conductor due to the internal resistance of that conductor. The voltage drop is calculated using Ohms Law. 

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