A greenhouse or a glasshouse (also greenhouse isolates mentioned) is a translucent construction, which makes a protected and controlled rearing possible of plants.
The cover - traditionally from glass, today often foils - increases on the one hand by the greenhouse effect the temperature, on the other hand one it protects against precipitation. By regulation of the air temperature and the irrigation an optimal growth of the plants and a certain controlling of other conditions (reproduction etc.) are possible.
At present largest greenhouse of the world is that of the Eden of project.
Plant and/or glasshouses are there in very different sizes of few square meters up to enormous palm houses (see upper picture). In an allotment already 1-2 cast-off windows are sufficient, in order to build a low greenhouse, whose climate can be regulated by opening the glass areas.
A greenhouse has at least
Furthermore many plant/glasshouses possess:
To the further equipment can belong:
One differentiates with the greenhouses depending upon interior temperature
During sun exposure it comes to a strong heating up in the greenhouse. The reason for it is a kind accumulation of heat: the energy of the solar radiation warms up first the soil, the plants and parts of the greenhouse, but again the radiant heat (infrared), delivered by them, is held back by the area.
This glasshouse effect (designation of J.Fourier) is often used with houses (winter garden) and roof areas (e.g. studios), but also generally speaking with Orangerien and locks. Air warmed up by the heated interior is cooled down from the outside with closed glass areas only few, because the air interchange is small. However nearly all infrared radiation of the glass and the building is back reflected into the area ("selective transparency").
However the interior temperature can increase to plant-harmful 35"°C and more on a normal sun day. Therefore one must know greenhouses also air, which takes place usually with roof or standing wall ventilation.
Newer types, so-called Cabrio greenhouses, can push their roof area together to a large extent. Thus the interior temperature can be steered in such a way that it corresponds nearly to the outside temperature. This leads to a clear quality improvement with cold cultures and during the summer months.
For the professional vegetable growing today plastic foils are often used, which cover partial large surfaces and whole valley soils. In El Ejido do not stand as many greenhouses covered with plastic tarpaulins as anywhere otherwise in Europe.
Most modern technology is used frequently first in research greenhouses. In the plant experimental plant PhyTec research center of the are used for example glasses from the solar industry, which maximum transparency and mechanical stability exhibit.