Ventilation in plant cultivation

Ventilation in plant cultivation

Ventilation in plant cultivation

Many plants require adequate ventilation if growing them is to work properly. The most important issue is, of course, the provision of appropriate amounts of carbon dioxide, i.e. the basic nutrient used by plants in photosynthesis, but thanks to a good ventilation system, you can also take care of the optimal temperature for plant growth and the correct humidity of its substrate and the environment in which it is located.

Prepare the room

Preparation of appropriate conditions for the cultivation of all kinds of plants should begin with the preparation of the so-called growbox, i.e. making the appropriate size of ventilation holes. This step can usually be skipped by people who have previously acquired professional plant growing tents.

The location of the vents

We know from the basics of physics that warm gas rises up and cool gas falls down. Therefore, it is best for your growbox to provide natural gravity ventilation through an opening at the base that will bring in fresh air and an opening at its top that will in turn remove warm and humid air. The most effective passive ventilation is by placing the holes diagonally across the growbox, opposite each other, but a different arrangement will also work properly.

Mechanical ventilation

For many plants, passive ventilation is far from sufficient for proper growth. Therefore, it is necessary to use mechanical ventilation, i.e. simply fans. You can choose between duct and radial fans. The choice of the type of fan is of secondary importance, because here, first of all, it is necessary to ensure its proper efficiency expressed in cubic meters of air pumped per hour of operation (m3 / h). In practice, the volume of the fan may also play a role. Effective mechanical ventilation for the needs of growing plants is such a ventilation that will be able to replace all the air in a ventilated room in just five minutes. The calculation of the required ventilation capacity is very simple. It is enough to calculate the cubature of the room in which the plants are located (length x width x height), multiply it by 12 (60 minutes / 5 minutes = 12) and compare the value obtained with the fan capabilities declared by the manufacturer. This is of course an approximate value and dedicated to cultivation with the use of HPS lamps. growbox wentylacja

Installation of ventilation

NMost often, in practice, mechanical ventilation systems are installed in the vicinity of the upper ventilation hole, which allows you to push air out of the growbox. It is important to install the fan firmly, as they are not silent devices, and any additional movement and vibration will increase the noise. Before buying a fan, it is good to read the opinions about it and use only proven products, as manufacturers often provide manipulated results, for example measured from a specific distance. The fan will run around the clock, so it can become a nuisance for the plant grower and his environment. installation of ventilation in a growing tent montaż wentylacji w namiocie uprawowym

Ventilation too loud

The solution to the problem of too noisy ventilation (which can occur even when choosing the optimal equipment) is the use of acoustic silencers. There are many types of acoustic silencers. The choice of a specific model is a matter of taste, conditions in a given growbox and budget. It is important to install them directly in front of and / or behind the fan. Mounting such devices in a configuration 2 before + 2 behind the fan will make the ventilation almost silent. Another solution to the noise problem are the fan speed regulators, which, however, also reduce their efficiency, and if the fan was not adapted to work with the regulator, its motor will become noisy. It is worth buying fans with factory-fitted regulators. Acoustic silencer for the fan Tłumik akustyczny do wentylatora

The fan inside the growbox

The question of whether it is worth installing a fan in the growbox itself is somewhat controversial, but the prevailing opinion is that the presence of the fan will allow the creation of air movement imitating natural conditions, which strengthens plants and softens the point nature of lighting sources.

The question of smell

In the cultivation of many plants, their smell becomes a problem. Especially if the smell is really irritating, which is not a rare phenomenon, it is necessary to use carbon filters to eliminate unpleasant odors. Such filters are available in many variants in terms of size and performance. You must base your choice on:
  • I. connection diameter - the diameter of the filter and ventilation ducts should be adjusted so that they can be connected efficiently;
  • II. efficiency - the filter efficiency expressed in cubic meters per hour must be higher than the fan efficiency in order not to block the air flow;
  • III. dimensions - the filter must easily fit in the designated place in the growbox.
Anti-odor filters are very effective, which is paradoxically their disadvantage. Any extra debris that appears in your growbox, such as cigarette smoke, will also be removed, but the filter's lifetime will drop drastically.

Installation of the carbon filter

Carbon filters should be installed in the mechanical ventilation system right in front of or behind the fan. Installing it in front of the fan will prevent any unpleasant odors from getting outside the growbox. In order for the entire ventilation system to work effectively, you need, of course, appropriate ventilation ducts that will connect its elements. Typical commercial tubing typically ranges from 100 to 315mm in diameter. It is best to use pipes corresponding to the diameter of the fan and filters and other possible ventilation elements, but you can also use adapters that reduce or increase the diameter of the pipes. The individual wires are connected with the use of cable ties.

The carbon issue

Plants need water, light and carbon dioxide to carry out the process of photosynthesis. In practice, the real problem is usually carbon dioxide, and it is this gas that determines how much we get from our plantation in growboxes. For very small-scale crops, if one is in their environment, there is usually no need to supplement carbon dioxide because our presence will result in sufficient carbon production. However, if there are more plants and they are excluded from the normal biome, as we are talking about, additional carbon dioxide may be required. Carbon dioxide can be produced on its own or you can purchase ready-made solutions to this problem in the appropriate stores. Own carbon dioxide production is very simple. It is usually obtained by creating a fermentation mechanism. For this purpose, we will need a two-liter bottle half-filled with water, the most ordinary sugar, a bit of baker's yeast, a rubber stopper with a hole (as in home wine production), and a rubber hose. Pour about 150g of sugar per liter of water into the bottle and a cube of yeast. Theoretically, half a cube per 100g of sugar is enough, but yeast has no cost and you can't overdose it. You just have to remember to crush them, and after placing them in the bottle, mix everything thoroughly. The bottle should then be closed with a rubber stopper and a hose should be inserted into its opening. The cocktail prepared in this way is enough for about 2 weeks of feeding the plant, regardless of how much water and sugar has been used - yeast, if added enough of them, will multiply quickly. Everything else will be a naturally occurring yeast fermentation process. The tubing will slowly feed the carbon dioxide into the growbox where the bottle will be placed. Keep in mind that carbon dioxide is heavier than air, so the end of the tube should be above the plant so that the resulting gas slowly falls on it, and does not accumulate at the bottom of the growbox, which would be the case if you simply put a bottle in it. Ready-to-buy solutions from specialist retailers can take many forms. The simplest of them are water-soluble tablets, but the effectiveness of this option is small. The best solution is to feed carbon dioxide directly from a cylinder filled with this gas, but this is only for large-scale growers, as plants rarely need that much extra food. Remember that carbon dioxide is a natural component of air, and ventilation will not allow it to run out.

co2 w growboxie


Home cultivation of plants using the so-called growboxes is not difficult and you can start it without major problems even after reading this text. To achieve success, you need a well-ventilated growbox, which means the need to make diagonal ventilation holes and install a fan, duct or radial, with the appropriate processing capacity. It's a good idea to have an additional fan mixing the air and cooling the lighting system in the growbox. If we are threatened by unpleasant odors, we should install a carbon filter in our ventilation system. We will build the ventilation system itself using ready-made ventilation ducts available for purchase in stores. We will connect them with cable ties. If our plants have high requirements for carbon dioxide or there are a lot of them in a small space, we will also need an additional source of carbon dioxide, which will be the best fermentation generator prepared on our own: a bottle with water, sugar and yeast. That's all. None of the required steps is particularly complicated and although the first time we may have different dilemmas regarding the practical organization of some issues, in fact even intuitively selected solutions can work very well.