We can think of a greenhouse in much the same way as a mini version of the Earth, with its atmosphere being made up of glass instead of the layers of gas found surrounding our planet. Much like the Earth as well the earthy greenhouse floor is heated as a result of radiant energy which is subsequently reflected back into the atmosphere (or, in this case, the inside of the greenhouse) as heat. The way in which the greenhouse produces and maintains a decent environment and atmosphere in which its inhabitants can thrive differs greatly from how the Earth’s atmosphere operates, however, as a greenhouse maintains a virtual closed system apart from the standard open systems found on the planet.

First, the greenhouse’s glass roof and sides allow for the entrance of the majority of solar wavelength radiation, with the glass tints generally reflecting the longer wavelengths that are produced as a result of the warmed Earth as well as the plants growing inside the greenhouse. Differing from the Earth’s atmosphere, however, greenhouses also prevent warm air from exiting as it rises from the ground inside. This is known as convection. In this way, greenhouses both use radiant energy and also save it via their limiting of convection.

Greenhouses must also contain methods of controlling the amount of radiant heat that comes in as well as the circulation of heat. Greenhouses that are on a smaller scale often use black netting which is draped over parts of the building in order to prevent incoming radiation, whereas larger greenhouses may have whitewashed sections to reflect excess energy. Air may also be circulated with the use of fans, which mixes the air as well as forces warm currents downwards from the roof. Fans also work by reducing the internal levels of humidity and condensation, which may well otherwise result in instances of rot and fungus.

The maintenance and operation of a greenhouse will also be complicated by daily weather events and cycles. For instance, cloudy and rainy days will result in far less incoming energy for the greenhouse, whereas sunnier days will bring in more. Also, instances of wind, rain and snow take heat from the glass and plastic covering, limited the ecosystem of the greenhouse. The changing seasons as well as changes in temperature can further alter such factors as the actual angle of incoming sunlight which will change the intensity of incoming solar radiation, in turn affecting the internal ecosystem of the greenhouse. In cooler climates greenhouse owners might also need extra heating and lighting sources and equipment in order to keep the atmosphere of the greenhouse stable and consistent for plants, particularly during winter.

Owners should be aware of the delicate climate balance on the operation of a greenhouse. For example, a sunny winter’s day may well cause a greenhouse to heat to problematic levels more quickly than a cloudy summer’s day, due to the fact that it is solar radiation rather than exterior temperature that play the critical role in heating the surface in order to facilitate the growth of plants. It is the management of air-mixing as well as the day-to-day operations that are so crucial in keeping the atmosphere stable and consistent for growing plants.