Silica aerogel could make Mars habitable

People have long dreamed of re-shaping the Martian climate to make it livable for humans. Carl Sagan was the first outside of the realm of science fiction to propose terraforming. In a 1971 paper, Sagan suggested that vaporizing ...

Part of the Pacific Ocean is not warming as expected, buy why?

State-of-the-art climate models predict that as a result of human-induced climate change, the surface of the Pacific Ocean should be warming—some parts more, some less, but all warming nonetheless. Indeed, most regions ...

Tropical soil disturbance could be hidden source of CO2

Thousand-year-old tropical soil unearthed by accelerating deforestation and agriculture land use could be unleashing carbon dioxide into the atmosphere, according to a new study from researchers at Florida State University.

Producing graphene from carbon dioxide

The general public knows the chemical compound of carbon dioxide as a greenhouse gas in the atmosphere and because of its global-warming effect. However, carbon dioxide can also be a useful raw material for chemical reactions. ...

Unexpected culprit—wetlands as source of methane

Wetlands are an important part of the Earth's natural water management system. The complex system of plants, soil, and aquatic life serves as a reservoir that captures and cleans water. However, as cities have expanded, many ...

Researchers detect bromine atoms in springtime Arctic

For the first time, researchers at the University of Michigan have detected bromine atoms in the atmosphere, and in doing so, have confirmed the reaction pathway through which mercury is removed from the atmosphere and enters ...

Turning food waste into bioplastics

An ingenious new solution being engineered at the University of Canterbury (UC) aims to turn food waste into valuable chemical components that could be used to make bioplastics.

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Greenhouse

A greenhouse (also called a glasshouse) is a building in which plants are grown. These structures range in size from small sheds to very large buildings. A miniature greenhouse is known as a cold frame.

A greenhouse is a structure with different types of covering materials, such as a glass or plastic roof and frequently glass or plastic walls; it heats up because incoming visible solar radiation (for which the glass is transparent) from the sun is absorbed by plants, soil, and other things inside the building. Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall. In addition, the warmed structures and plants inside the greenhouse re-radiate some of their thermal energy in the infra-red, to which glass is partly opaque, so some of this energy is also trapped inside the glasshouse. However, this latter process is a minor player compared with the former (convective) process. Thus, the primary heating mechanism of a greenhouse is convection. This can be demonstrated by opening a small window near the roof of a greenhouse: the temperature drops considerably. This principle is the basis of the autovent automatic cooling system. Thus, the glass used for a greenhouse works as a barrier to air flow, and its effect is to trap energy within the greenhouse. The air that is warmed near the ground is prevented from rising indefinitely and flowing away.

Although there is some heat loss due to thermal conduction through the glass and other building materials, there is a net increase in energy (and therefore temperature) inside the greenhouse.

Greenhouses can be divided into glass greenhouses and plastic greenhouses. Plastics mostly used are PEfilm and multiwall sheet in PC or PMMA. Commercial glass greenhouses are often high tech production facilities for vegetables or flowers. The glass greenhouses are filled with equipment like screening installations, heating, cooling, lighting and may be automatically controlled by a computer.

This text uses material from Wikipedia, licensed under CC BY-SA