A greenhouse (or hothouse) is intended to crop production,
with a usually translucent outer shell of glass or plastic, which allows
control of temperature, humidity and other environmental factors to encourage
the growth of plants.
In the former Spanish gardening, the greenhouse was
called cold stove.
Seize the effect of solar radiation from the sun, passing
through a glass or other translucent material, heats the objects inside; these,
in turn, emit infrared radiation, with a length of greater than solar wave,
thus cannot pass through the windows return to their getting caught and
producing heating.
Emissions from the sun to the earth are shortwave land while
abroad are in long wave.
The glass or plastic used for a greenhouse works as
selective transmission medium for various spectral frequencies, and its effect
is to trap energy within the greenhouse, which heats the indoor environment.
Also it serves to prevent heat loss by 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 automatic cooling self-ventilation.
In the absence of a coating, the absorbed heat is eliminated
by convection currents and the emission of infrared radiation (wavelength above
the visible wavelength).
The presence of crystals or plastics prevents the transport
of heat accumulated outward by convection and obstructs the exit of a portion
of the infrared radiation. The net effect is the accumulation of heat and
increase in temperature of the enclosure. View (technical) solar greenhouse for
a more detailed discussion of technical work solar greenhouse.