Greenhouses and the Science behind them


What is a greenhouse?

A greenhouse is a wall and roof structure which is usually made of transparent material which allows sunlight to penetrate inside. Mostly greenhouses were made up of glass but recent technology allows us to even make greenhouses with other materials. The chief purpose of having a greenhouse is to house plants in them that need regulated climatic conditions to grow and mutate.

Why are greenhouse called so?

The greenhouse may be called so because they house green plants within them. the idea of growing plants within them is because the varieties of plants that cannot grow in natural climate can be grown with regulated temperature in the greenhouse and thus can ensure availability of it throughout the year. If you are interested in green house / gardens click on this link A greenhouse is also referred to as a glass house because of the material that is used in building it and a hot house because the temperature inside the greenhouse is much higher than the atmospheric temperature outside of it.

How is the temperature inside warmer?

The temperature inside the greenhouse is indeed much higher than the outside atmospheric temperature and this is because of the insolation of the sunlight. In simpler terms the solar rays that pass through the glass roof and glass walls of the place is absorbed by the floor, and the contents of the greenhouse and they remit the energy. But since glass allows only the solar radiation to come in but does not allow the solar radiation that is re emitted from escaping, the heat in the greenhouse stays higher than the outside temperature.

Another reason why even small amount of heat is not able to escape is because the greenhouse is closed from all the sides. Therefore the heat cannot even escape through the roof of the structure.

greenhouse1-600x360The greenhouse effect:

What transpires inside a greenhouse also is similar to what happens in our own planet. The heavier gases such as carbon dioxide and methane present in the atmosphere act like a glass shield that does not allow all the heat to escape from the surface of the earth. A good percentage of warmth is still present in the earth’s atmosphere even if the sun sets. This is the precise reason why nights are tolerable by the living beings.

Consider there to be no greenhouse effect in the world, then by nightfall, all the heat of the world would dissipate back into the space and the nights would be freezing cold because the sun’s heat and warmth have returned back as radiation into the space.

Quantitative studies recommend greenhouse can be made economical:

Quantitative studies have proven that if the glass walls and the roof of a greenhouse are tinted with dyes that prevent even minutest radiation through the process of convection, they can reduce the electricity cost by about a whopping ten percent. Further research is on in this field and the scientists are working on experiments to prove if normal anti reflective glass can also substitute for the dyed glasses.

Do the greenhouses need ventilation?

Yes, the plants need fresh air inside the greenhouse. Lack of fresh air can lead to problems in the growth of the plants and also interfere majorly in the photosynthetic or the food making ability and the respiratory functions of the plants.

The efficient ventilation of the greenhouse seeks to maintain a correct balance between the temperature and having the right amount of humidity inside its chambers in order to be positively useful for the plants and not have any detrimental effect on the plants.

kent-garden-greenhouseArtificial heating:

In colder countries, massive greenhouses are built in order to ensure availability of food throughout the year. The main challenge in heating up of the greenhouses in such places is that the heat that is artificially generated inside the greenhouse dissipates from the openings which are originally built for the suns radiations to filter in. There is a lot of money spent on heating the premise as heat so generated continually escapes into the atmosphere.

How are the greenhouses heated?

The greenhouses around the globe recommend the use of green energy. Very seldom, non -renewable sources of energy is used for heating and that also when there is no other alternative to use. The additional heat in a greenhouse is mostly generated through the use of natural gas or by warm electric furnaces.

Some greenhouses also have the ability to use passive heating technology like solar energy that is harnessed and stored in cells through the warm day and to be used at night. Even wastes from livestock rearing can be used to keep the greenhouse heated at nominal rate. One another concern in maintaining the greenhouses is to monitor the temperature and adjust the heating to its conditions.