Ventilation

why is ventiliation important?

Ventilation not only helps with temperature, carbon dioxide and humidity, it can also help strengthen the stems of the plant. Outdoors, this naturally happens with the wind blowing the plant from side to side which can increase the plants resilience and help it to become stronger. You can recreate this by putting a fan close to the leaves of your plant, so they are constantly moving in the breeze. This breeze can also help to keep of insects, bugs, and other parasites, as well as dust. 

indoor grow equipment
(CC BY-SA 4.0)

how to get the best environment

During the first few weeks of the growth cycle, the fans should be placed directly over your plants, making sure the wind is going right through the leaves. Later on, in the flowering stage the fan can be moved to the space between the top of the plant and the lighting. This will move any excess hot air and disperse it around the room.

It is also a good idea to have several ventilators or fans placed around the room, so every corner of the room receives fresh circulated air. Try having a fan blowing over the top of your plants and one pushing air up from underneath. Ensure the breeze is not too strong as this can start to damage leaves and stems.

You should place the exhaust fan at the opposite end of your air circulating fan. This will create a stable and balanced climate in the room. The exhaust fan can help with removing the very potent smell that will come from your room during the flowering stage, as well as extracting heat and humidity. It is also important to have some kind of pipe or hole that allows in fresh air, this could be through a window or a pipe leading from a window. 

indoor grow tent

ventilation in a grow tent

Grow tents are an extremely popular way to grow cannabis due to the simple nature of setting up and being easier to maintain. How big your ventilation system will be, will depend on how big your grow tent is and the power of the lighting you will be using.

Fans and extractors can by attached to the inside of the tent’s poles using a simple cable tie. Try to this before you put up the lights, as it can be awkward once the lights are up. Use rope ratchets to then install your grow lights in your tent. If using a carbon filter, connect this to the light by using ducting (and ducting clamps). Then connect the light to the exhaust fan in the same way and then another tube of ducting from the fan, to allow the hot air to leave the grow tent. You will also want a tube or hole to allow in fresh air and leave a window open. Trying to keep all the tubing as straight and short as possible for a more effective system. 

types of equipment you will need

Exhaust Fan

Exhaust fans (or extractor fan) work by extracting hot and humid air from inside a confined space, which then allows fresh air to enter (this could be through a hole, pipe, or open window). The hot air goes through a ducting pipe that leads outside. A 4” exhaust fan would suit a 4’x4’ grow tent and a 6” fan would be great for 5’x5’ tents.

Carbon Filter

Carbon filters are attached to the exhaust fans from inside the grow tent. Their job is to help illuminate odours, smells and smoke and they do this by the air being pulled through the filter before being extracted outside. It is a way to purify the air and take away that vey potent smell you will have during flowering stage. For a 4” exhaust fan you will need a 4” carbon filter, and so on.

Duct Clamps

Duct clamps are great for attaching your fans and ducting together in an efficient and easy way. They provide a simple way to attach equipment together without the use of tools.

Ducting

Duct hoses are the pipes that are attached to your fan, to extract hot air out of the system. Semi-rigid flexible ducting is recommended for a good air flow through your grow tent.

Intake Fan

These work with the exhaust fans but do the opposite. Instead of bringing hot air out, they bring cool, fresh air in from outside the grow space. The fan should be not quite as powerful as the exhaust fan and the two will work together to provide a stable environment for your plants. They help to restock the volume of oxygen and carbon dioxide in the air.

Rotating Clip Fan

This is the fan that pushes through the air that is in your tent and allows the fresh air to be distributed evenly through the room. This should create a nice gentle breeze through your plants, mimicking the wind if your plant would be growing outdoors.

Noise Reducers

If you have a noisy exhaust fan, then this piece of equipment will help to lower the noise levels. It is attached to the end of the exhaust system and will absorb the majority of noise from your fan.