Do I need a fan in my grow room?

The Cannabis, when grown in a room, utilize their characteristic of absorbing almost 100% of Carbon dioxide present in the air thus necessitating the air to be recycled and refreshed by any means. Usually, grow rooms don’t have natural ventilation, therefore, the installation of a fan is strongly recommended in a grow room.  Installation of fans is considered in a manner that plants placed at the farthest corner of grow room; also get fresh air and sufficient carbon dioxide. Correct and appropriate installation of fans will not only help easy and comfortable breathing by the plants but will also ensure eliminating stagnant air bubbles ultimately preventing fungi and diseases. [1]

Why do you need to ventilate Your Grow Room?

Stagnant air along with the content of moisture is a straight recipe of producing fungi and inviting several diseases to Cannabis plants when grown in a grow room or tent. A moderate flow of fresh air is unavoidably essential for the survival of fragile plants especially those which are at far place from an air opened door, window or vent. Good breathing leads to an improved photosynthesis process after which plants absorb essential minerals from the soil thus leaving a positive and pleasant effect on the overall growth of the plant.  A healthy flowering season with strong leaves, branches, and trunks is only possible with minimally enhancing friction to air; which results in improved buds and flavor. Generally, airflow for a grow room is recommended on 15 minutes cycle for dry grow; whereas, a constant airflow is suggested for a humid grow environment.[2]


Remove Excess Heat

The cannabis plants are very sensitive for temperature and surroundings and it is an uphill task to manage temperature through conventional vent unless you install some blower or fans arrangement.Temperature control in grow room or grow tent is extremely difficult due to restricted flow of air; that is why many researchers have recommended the installation of fans in these rooms.[3] Conventional vents can only be helpful to reduce heat only when they are supplied with fresh air through fans which suck fresh air from outside and push that air reach at the farthest place in a grow room. Absorption of carbon dioxide by the cannabis plant results in the air to be stagnant in the form of bubbles which in the presence of excessive heat and moisture brings many health issues for the plants. Heats are generated through various chemical processes naturally happening in plants as well as from artificial grow lighting; which can only be controlled through the installation of fans. Heat dissipation is extremely necessary for grow room as if heat is not dissipated; the temperatures may go as higher as exceeding 70O F putting the fragile plants in extreme breathing and growing difficulty. Greater temperature can be a potential hazard of heatstroke for the plants. The outcomes of increased temperature could be slowed down growth, reduction in harvesting and serious infections subsequently to the death of the affected planted. Increased exposure to excessive heat can be catastrophic for the Cannabis plants especially for those which grow hydroponically because in this method of growing plants roots are openly exposed to the environment instead of being covered by the soil and the pot. There are a lot of tactics being employed to reduce the heat and managing temperatures within prescribed safe limits ultimately resulting in safeguarding cannabis to allow their free and rapid growth. Installation of appropriately sized fans at suitable places can be very helpful in reducing heat and keeping plants safe from heatstroke and associated issues.

Control Humidity

Water intake is essentially required at all stages of Cannabis growth; the requirement of water for a particular plant keeps on changing as per humidity level of the grow room.  If the humidity in the atmosphere increases; the requirement of water decrease as the plant absorbs moisture content through its leaves.[4] On the contrary; plant needs to get more water through its roots if the humidity level in the atmosphere is low and moisture content in the air is either significantly low or absent. It’s the humidity that defines and controls the liquid intake need of a plant; water taken from the soil through routs is much beneficial for the plant as it contains multi-mineral contents in it and keeps the plant growing constantly. An atmosphere with controlled temperature and humidity can help assess the water needs of the plant; however, it cannot be the ultimate solution for the prevention of anything going wrong with the plant.


Keeping humidity levels at an appropriate scale is extremely good for strength, health, and rapid growth of plants particularly the cannabis and other leafy plants like it. Plant growth can be much faster and healthier if the plantation is done correctly and recommended humidity levels are maintained.  Moreover, when a plant starts producing the buds in the pre-flowering stage ultimately making it ready to be harvested in the near future; manipulation of humidity levels is as essential as unavoidable. The correct level of humidity results in the rapid growth of the plant to create more quantity of Rasin or glitter which possesses THC and high levels of cannabinoids and helps to avoid Cannabis from being under direct attack by the mold. Poor management of humidity can lead to serious disaster; many people experience many problems in an already grown cannabis plant in a grow room after those become victims of poor humidity control.  The most common problem faced in Cannabis due to inappropriate levels of humidity is white powdery mold; which is a fungal disease and caused due to over humid surroundings. It can be prevented by taking appropriate measures to lower the humidity level to the recommended limits.


Prevent Pests and Diseases

There are certain very common diseases which spread out in the plants and kill them in due course of time. Many of paragons can be seen while growing the Cannabis; these are real threats for these delicate plants. The most common question here is how to identify pests and what’s the best method to eliminate their presence ultimately bringing the destruction of the plant.  The farmers constantly growing the Cannabis will be in a position to explain how uphill battle is it to control pest attack on the crop when it once gets affected.[5] If you don’t clean the infected parts or plants and isolate those from healthy ones; those will kill the healthy plants as well and that too in hours. On the other hand, pulling the affected plants out from the field or grow rooms is also very difficult as it involves a lot of time, effort, labor, and financial burden. It is, therefore, strongly desirable that precautionary steps must be taken to avoid any chance of diseases and insects, etc. The crop area must be cleaned on regular intervals; light and vent of the area must be looked after and if deemed necessary the pesticide sprays/ medicines are to be administered after consultation with the professionals. Grow space must be secured for any such threats by using various techniques.[6] Few things which are considered most important are being highlighted in the following lines:


  • Grow rooms may be kept ventilated by arranging fans and by keeping the open vents at appropriate places.
  • Grow rooms may be provided with sealing arrangement and can be isolated from the outside atmosphere to keep the chances of intrusion of pests minimum.[7]
  • Grow rooms or grow tents are to be managed in a way that clanship operations could be easily carried out.

It is needless to say that the level of protection from pests, insects, and disease will guarantee the increased return of the investment made on the crop by giving rapid growth to the plants and producing very nice flavors of the healthy buds.

Control the CO2

Carbon Dioxide or CO2 is an extremely important thing for any plant’s growth and yield. Providing sufficient Carbon Dioxide in Grow Room results into improving all function of growth thus improving the health conditions of the Cannabis plants. Rational Carbon Dioxide can play wonders with the plants and can give dramatic results. Every plant requires almost 17 compulsory ingredients for better reproduction and good growth; however, Oxygen, Hydrogen, and Carbon are the most important element out of these. These three elements only constitute around 95 percent of the dry mass of a plant. Indoor cultivation generally involves the provision of light putting a barrier in the way of the growth of a plant, it is, therefore, very important to ensure that grow rooms are provided with sufficient light, suitable quantity of air andwell-organized Carbon Dioxide.[8] A volume of about 370 PPM of Carbon Dioxide always remains present in atmospheric air, therefore, provision of ample light ventilation and air circulation is a good start for the rapid growth of a plant. In a closed grow room where less sunlight is available, a large quantity of Carbon Dioxide gets consumed which reduces the quantity of CO2 in the atmosphere which can create a consistent problem for the growth of the plant. Deficiency of Carbon Dioxide can adversely affect the health of buds and also can deteriorate the flavor. On the other hand; ample quantity of CO2 remains present in the above ambiance levels; which gives immense support to Cannabis to grow to a healthy level and to produce health and best-flavored buds. Cultivators can get an increase in the crop of Cannabis somewhat close to 30 to 50 percent of the expected crop if Carbon Dioxide gets increased up to 1500 PPM. By employing these tactics in combination with good ambiance and fresh air can enable the Cannabis plant to flower and fruit earlier than expected time. Targeting a good return over an investment upon Cannabis cultivation, an investment upon CO2 can be more advantageous and beneficial.

Manage Wind Stress

Every living being likes and essentially needs an air intake. A gentle breeze is liked and loved by every living creature including plants. For activation of hormones and building the strength of the plant; it is a matter of concern that there must not be any stress of wind blow. Blowing of wind can facilitate the chemical reactions within the plant structure. What wind does is; it waives and moves the stem of a plant which results in the production of ethylene inside the plant which stimulates further growth of the plant. Management of strength of wind blow defines the harmonious response inside the plant thus improving the growth speed of a Cannabis plant.[9] This ethylene normalizes numerous characteristics of the plant in terms of health and growth. The soft wind waving the stems of plants brings aging factor and maturity in the plant. By throwing unbearable strong winds over the fragile plants of Cannabis can also be dangerous for the strength of the trunk. The plants should have sufficient strength to stand firm in the blowing winds, they cannot stand upright if the wind gets strong. Wind if not managed to stay within limits it can be very dangerous for Cannabis in their flowering season and fruit season by damaging flowers and fruit. On the other hand; if wind blow is not managed and it blows more slowly and more softly, it can allow insects and pests to house in the moist hot atmosphere; ending up in the failure. Generally, stems with a powerful base truly support the whole weight of plant; it provides fruit to the plant and helps it to grow to significant health parameters. However, the strength of stem must not be the ultimate goal, it should have a soft but moderate strength to provide roomed Cannabis to grow properly and bring more return to the hard-earned investment.

Types of Grow Room Fans

It is a matter of great importance to assess the need of ventilation in a particular grow room and to provide it with a correct and appropriate type of fan in order to throw a controlled yet sufficient quantity and speed of the air. Generally, there are two main types of growing fans; Exhaust Grow fans and Vent grow fans. Vent fans or intake fans bring the air from outside to inside whereas the exhaust fans throw the used air (CO2 Extracted air) to outside a grow room. In subtypes of the fans, we may include Oscillating fans and air extractor fans.[10] The major purposes to ascertain the need of a particular fan can either be for controlling the humidity, to inject CO2 inside the grow room and to ensure the provision of sufficient Carbon Dioxide and other important elements of the air. Size of the fan can also be ascertained through knowing the size and location of the grow room.

Exhaust Fan for Grow Room or Tents

Combination of fan and flier can be very beneficial for the grow room atmosphere but only in case if it is intelligently and smartly installed. Exhausts fans are a very essential part of any grow room or grow tent.[11] When the air gets circulated through the room and plants extract the CO2, Hydrogen, Oxygen and other vital elements from the air, the air bubbles get stagnant in the grow rooms; thus not allowing it to stay stagnant for a longer time and throw it outside the grow room with the help of exhaust fans. When the stagnant air stay in the grow rooms for the longest time those can be harmful to Cannabis.

As earlier explained, ventilation of the Cannabis grow rooms is very important; it throws the contaminated air into open atmosphere and Fresh air enters into the grow room carrying an ample quantity of CO2 enabling the air to be a source of health and freshness for a plant, flower as well as the fruit of the air.


Intake fan for Grow room or Tents

Once the stagnant and unusable air is thrown out by the exhaust; a vacuum is created inside the grow room necessitating the fresh air to enter into grow room and take place of the stagnant air bubbles. Speed of this air is usually not suitably good for the plants as we have already told. To manage speed, strength, and contents of the air beneficial for the plant; it is very necessary to install intake fans for throwing outside air inside.[12] Ventilation is a cumbersome process which can be majorly divided into the whole cycle of throwing the air outside and bringing new fresh air inside.  Intake fans are usually set upon a specific speed which helps to carry the essential contents in the air. Intake fans speed should be put on adjustable limits so that the maximum number of plants can be given with the benefit of fresh and cool air which ultimately supports the growth, flower, and fruit.

How to Ventilate Your Grow Room

Ventilate is a very famous term that is very widely used for both the intake and exhaust function of the air. There are numerous ways to ventilate the rooms of cannabis.  Some people simply use the holes covered with the net. Holes are made for air intake and outflow with their constant and unchanged contents of the air. These square wholes can be provided with exhaust fans which instantly collect the used and stagnant air bubbles form inside the grow room. Another method of ventilating the grow room is installing the whole arrangements of intake, like exhaust and intake types of fans can be helpful.[13] A good ventilation system can be extremely helpful for the plants’ growth, bringing flowers on to it and providing fruits in reasonably less time than the conventional methods used for growing Cannabis. Giving plants a general impression, the exposure of the plants to the air is the prime responsibility of the ventilation system. It helps fighting many diseases among the plants by providing them the right quantity of Carbon Dioxide, Oxygen, Hydrogen, and many other positive nutrients.   The good ventilation system also helps maintain controlled dimensions and controlled environment by practically managing the Heat, air and CO2 Levels of the grow room.  Infect having positive control over CO2 levels, temperate and good ventilation; put the plants under rapid growth, more healthy buds and profitable return of hard-earned money invested in the cultivation of the Cannabis.  All these arrangements must assist and support the plant to grow rapidly and safely. This variable should be ranged between the allowed limits of the international standards; to provide a plant with the essentials and minerals needs.


Reference Links:



(3) (Heat reduction)

(4) (humidity control)

(5) (Pests & Diseases)

(6) (Pests & diseases)

(7) (how to prevent pests)

(8) (Control CO2)

(9) Control wind stress

10) Grow Room Fan types.

(11) Grow tents exhaust fans

(12) intake fans

(13) ventilation