Growroom
Encyclopedia
A growroom is a room of any size where plants are grown under controlled conditions. The reasons for utilizing a growroom are countless. Some seek to avoid the criminal repercussions of growing illicit cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s, while others simply have no alternative to indoor growing. Plants can be grown with the use of artificial light, sunlight
Sunlight
Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the Earth's atmosphere, and solar radiation is obvious as daylight when the Sun is above the horizon.When the direct solar radiation is not blocked...

, or a combination of the two. Due to the heat generated by high power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

 lamps, grow rooms will often become excessively hot relative to the temperature range ideal for plant growth, often necessitating the use of a supplemental ventilation fan
Fan (implement)
A hand-held fan is an implement used to induce an airflow for the purpose of cooling or refreshing oneself. Any broad, flat surface waved back-and-forth will create a small airflow and therefore can be considered a rudimentary fan...

.

Growing methods

The plants in a growroom can be grown in soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

, or without soil via means such as hydroponics, and aeroponics
Aeroponics
Aeroponics is the process of growing plants in an air or mist environment without the use of soil or an aggregate medium . The word "aeroponic" is derived from the Greek meanings of aero- and ponos . Aeroponic culture differs from both conventional hydroponics and in-vitro growing...

. Not only is growing in a soiless medium more cost effective, sometimes one also gets a much higher yield, as well as faster fruit maturation.

Soiless mixes usually carry 0% nutrients so the gardener can utilize the perfect combination of nutrients for the crop. Vermiculite
Vermiculite
Vermiculite is a natural mineral that expands with the application of heat. The expansion process is called exfoliation and it is routinely accomplished in purpose-designed commercial furnaces. Vermiculite is formed by weathering or hydrothermal alteration of biotite or phlogopite...

, perlite
Perlite
Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently...

, coconut husk and rockwool are the most popular mixes for indoor cultivation.

Lighting

The three most common varieties of lighting for indoor growing are High-intensity discharge lamp
High-intensity discharge lamp
High-intensity discharge lamps are a type of electrical lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. This tube is filled with both gas and metal salts. The gas facilitates the...

s (the most prevalent for this application being: high pressure sodium for flowering and metal halide for growing), Compact fluorescent lamp
Compact fluorescent lamp
A compact fluorescent lamp , also called compact fluorescent light, energy-saving light, and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent lamp; some types fit into light fixtures formerly used for incandescent lamps...

s, and traditional Fluorescent lamp
Fluorescent lamp
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful...

s.

Incandescent and halogen lamps generate excessive heat per watt, with a low lumen to watt ratio.

LED lights are becoming more popular for growrooms due to their low energy requirements and low heat output. Recent advances such as automotive grade 6 watt LEDs have entered the LED grow light market.

Luminous efficacy

High Intensity discharge lamps (HID) have the most efficacy
Luminous efficacy
Luminous efficacy is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power. Depending on context, the power can be either the radiant flux of the source's output, or it can be the total electric power consumed by the source.Which sense of the term is...

 in terms of Lumen (unit)
Lumen (unit)
The lumen is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux...

s of light output vs. power
Electric power
Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is the watt.-Circuits:Electric power, like mechanical power, is represented by the letter P in electrical equations...

 input. Compact fluorescent are slightly less efficient than HID lamps. Traditional fluorescent lamps generally do not produce enough concentrated light to be a primary light source for most indoor growing operations. Fluorescent and compact fluorescent lamps are excellent light sources for young plants (seedlings). They are also excellent for supplementing the light generated by primary HID lamps.

Light is essentially "plant food"; everything else that we provide to a plant serves the purpose of helping it digest and use the light. As the plant grows larger, it requires an increasing amount of light. There is no substitute for light: if the amount of light received by the plant is insufficient, the plant will stretch, and / or growth will slow to a halt

For indoor gardening one of the most important topics is therefore the amount of light energy striking the surface of the plant ("incident light"), which can be measured in lux
Lux
The lux is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area. It is used in photometry as a measure of the intensity, as perceived by the human eye, of light that hits or passes through a surface...

(lux = lumens / area illuminated in square metres).

Ventilation

As a controlled environment, grow rooms offer many advantages over outdoor alternatives. However, without adequate ventilation, the plants may consume resources, like oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

 and carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

, faster than they can be replenished. Adequate gas exchange is necessary for optimal plant growth. Ventilation is also an important method for maintaining an optimal temperature for plant growth.
Advanced grow room even include air conditioning to keep running temperatures down, as well as CO2 to boost the plant's growth rate.

Clandestine usage

Cultivating marijuana is illegal in many countries, and thus some choose to grow marijuana indoors in an attempt to conceal their activities.

Law enforcement
Law enforcement agency
In North American English, a law enforcement agency is a government agency responsible for the enforcement of the laws.Outside North America, such organizations are called police services. In North America, some of these services are called police while others have other names In North American...

 authorities attempting to locate grow rooms are known to search the records of electricity providers for signs of excessive electrical consumption and employ airborne thermal imaging cameras/FLIR/infrared cameras).

Growers respond to the use of thermal imaging cameras by isolating and decoupling rooms physically from the outer walls of buildings, and directing ventilation exhaust into a chimney.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK