Tiny particles lead to brighter clouds in the tropics

When clouds loft tropical air masses higher in the atmosphere, that air can carry up gases that form into tiny particles, starting a process that may end up brightening lower-level clouds, according to a CIRES-led study published ...

Investments to address climate change are good business

An internationally respected group of scientists have urgently called on world leaders to accelerate efforts to tackle climate change. Almost every aspect of the planet's environment and ecology is undergoing changes in response ...

New study identifies causes of multidecadal climate changes

A new reconstruction of global average surface temperature change over the past 2,000 years has identified the main causes for decade-scale climate changes. The analysis suggests that Earth's current warming rate, caused ...

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 ...

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.

page 1 from 23

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