Energy & Green Tech

Merkel: No way back on German plan to end nuclear power use

Chancellor Angela Merkel on Thursday defended her decision to end Germany's use of nuclear power next year, but acknowledged that it will make it harder to reduce greenhouse gas emissions in the short term.

Energy & Green Tech

Study puts charge into drive for sustainable lithium production

An important new study by researchers at the U.S. Department of Energy's (DOE) Argonne National Laboratory has yielded critical fresh insights into the lithium production process and how it relates to long-term environmental ...

Business

Toyota targets carbon-neutral plants by 2035

Toyota, the world's biggest automaker, said Friday it aims to make its production carbon-neutral by 2035, replacing the previous target date of 2050.

Energy & Green Tech

Chile inaugurates Latin America's first thermosolar plant

Chile on Tuesday inaugurated Latin America's first-ever thermosolar energy plant, a vast complex dubbed Cerro Dominador in the Atacama desert that gives a boost to the country's quest for carbon-neutrality by 2050.

Energy & Green Tech

Developing the world's 'hottest' heat pump

The heat pumps we use to heat our homes and domestic water operate at temperatures of between 30 and 60 degrees, but many industrial processes require much higher temperatures—and some industries require an entirely different ...

page 1 from 13

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