How Long to Keep Fans on in Grow Room?

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There is no particular time that is needed to keep the fans on in Grow Room. However, there are critical factors that will determine the time.

In this article, we will share with you factors that will determine the time you need to keep your fans on in a Grow room.

But before we do that, it’s important to understand why we need a Grow tent fan.

Why Do You Need a Fan in a Grow Room?

In the natures, wind flows normally, and it’s necessary for plant growth. When you decide to place your Grow tent indoors, you also need to provide similar conditions as in the natures.

The wind is an essential requirement for the plants that grow in the natures. It supplies the wind that is needed by your plants.

The following are some of the reasons why you need a fan inside your grow tent.

  1. To Improve Air Circulation

Plants take in carbon dioxide and release oxygen. For the effectiveness of the plant breathing, you need a fan to bring in the fresh air and remove air with excess oxygen from the grow tent.

If the air circulation is not adequate, the plants start to become yellow or losing their green colour.

  1. Cool A Grow Room

Something else you have to deal with in a grow room is temperature build-up. If you are going to get the best from your grow tent, the temperatures need to be kept at an optimum. A fan will supply cool air and remove heat build-up.

  • Control Humidity

Sometimes your Grow tent will become too humid. If this situation is left, you are likely to experience some problems such as low yields or condensation.

A grow fine will supply dry air and remove the excess humid.

The same will happen when the humidity is low. A fan can supply humid air from outside and improve the overall Grow room humidity.

  1. Strengthen Plants

In nature, the wind blows over the branches and make them strong. They become strong as they try to resist the pressure from the wind. As a result, the plant grows strongly.

The same happens in a grow room. The Grow tent fan blows air over the plant stems. As a result, they become strong. When it comes time to yield, the branches don’t break because they are already strong.

  1. To Remove Odor and Clean Grow Room Air

Time over time, you will have bad smell and chemicals building up in your Grow room. To get the best out your plant’s you need to control the smell before it affects your plants.

A fan will ensure that fresh and clean air is supplied into the Grow room all the time.

Factors that Determine the Time You Need to Keep the Fan On

1. Size of Your Grow Tent and Fan CFMSize of Your Grow Tent and Fan CFM

The need for the airflow from your fan will depend on the size of your tent. Small grow tent will require small intervals of turning the fan on.

On the other hand, a large, grow tent would require the fan to run for many hours.

When it comes to the size of your grow tent, you also need to understand the CFM of your grow tent. If the CFM is higher than the volume of the grow tent, you need to keep the fan in a few hours. A low fan CFM will need to run for many hours.

However, to get better yields for you to grow tent, you need to use the right CFM for the size of your tent.

Read our article on How to Calculate your Grow tent CFM and know the right fan you will need

2. The Need of the FanThe Need of the Fan

In Your grow tent you will need a fan for various reasons. Some of the reasons you need a fan to include ventilation, air filtration, and all other factors discussed above.

These needs will highly determine the usage of the fan in your Grow area.

For example, if you are using the fan for air filtration; you can only turn the fan off when you have completely filtered your air. In other cases, if the fan was to lower humidity, you can only turn it off when the humidity is low to the desired levels.

This is why we recommend that you first understand why you need the fan in a Grow room. Once you do that, it will be easy for you to know how long to keep fans on in grow room.

3. Light and Dark HoursLight and Dark Hours

The need for wind in your grow tent will be different at different times of your growth plan. You will need low airflow when the lights are off as compared to when the lights are on.

When the lights are on, your plants produce a high amount of moisture and heat. It’s therefore advisable to keep the light running throughout when the fans the lights are on. It will help reduce the humidity and at the same time, lower temperatures in a Grow tent.

When the lights are off, you need to reduce the speed of your fans after around 15 minutes. You can also set the fans to the only run at most 15 minutes per hour. This air circulation need will help you give enough airflow when its dark.

It’s important to note that when it’s dark, you experience less heat from the plants and also no much water is released by the plant.

4. The Stage of Your Plant

At different stages, your plant will require a different amount of airflow. It’s also important to pay attention to the stage at which your plant is at. If your plant is at a stage that needs more airflow, you keep the fan running for many hours and if it’s not within that stage, you supply adequate airflow.

The following are the stages which your plant will undergo.

Seedling Stage

Seedlings are vulnerable to diseases. Therefore, you cannot allow any case of damping in your Grow room. As a result, you need to keep a continuous air supply at all times.

Based on the humidity and temperature of your Grow tent, you can set the appropriate temperatures.

However, at this stage, provide a gentle breeze that won’t harm your plants.

Vegetative Stage

At this stage, have moderate airflow. During the lighting, hours provide airflow at its maximum. But when it comes to a dark time, reduce the speed of airflow or turn off the fans completely.

At the vegetative stage, the plant will need enough airflow to strengthen its branches and also ventilate the Grow room.

Flowering Stage

This stage its critical for farmers. You need to keep the fans running during the light hours. This will help prevent humidity and heat affect your yield.

During the dark hours, keep the fan off after 1 hour. Let the plant flower without any disturbance.

However, if you are dealing with high humidity and bad smell, keep the fan running through the dark hours but on a very low speed.

How Long to Keep Fans on in Grow Room

Best Fan To Buy For Your Grow Tent

TJERNLUND M-67 Inline Duct Booster Fan

The fan attains a power output of 460 CFM. This means it can run for a long time without changing its performance.

Key Features

  • Made with strong and high-end materials
  • Efficient blade design to blog a huge volume of air
  • Super quiet fan

The fan is available on Amazon. Click here to check the latest price and buy it from Amazon.

AC Infinity Cloudline S6 (Our Top Pick)

The fan is perfect for a mid-sized grow tent. It achieves an airflow of 351 CFM.

Key Features

  • Ideal strength for a mid-size room
  • Extremely quiet
  • The variable setting for efficient power consumption

The fan is available on Amazon. Click here to check the latest price and buy it today.

Vortex 347 CFM S Line S-600 Fan 6”

With it, you will plant everything you would wish to plant in your tent or indoors.

Key Features

  • Mounts easily
  • Convenient with different speed controllers
  • A super quietest tent grow fan even at the highest speed

The fan is available on Amazon. Click here to check the latest price and buy the fan from Amazon today.

Terrabloom 10” Inline Duct Fan

It delivers a high airflow of up to 1065 CFM. At the same time, it’s cost-effective.

Key Features

  • Runs optimally for a longer period
  • Ultra-quiet fan
  • A powerful CFM coverage with a low energy consumption

The fan is available in the market. Click here to check the latest price and buy the fan today.

Hurricane Inline Fan

This makes it a perfect choice for anyone with a small grow area.

Key Features

  • Durable construction
  • Super Quiet Fan
  • Ease of installation

The fan is available on Amazon. Click here to check the latest price and buy it from Amazon today.

Parting Shot

Now you know how long you need to keep your fan on at any situation. Therefore, buy either of the fans we have recommended in this article and install it over your Grow room.

Relevant Resources:

1.Cooling Grow Room with Ice- Everything You Need to Know

2.Grow Room Temperature Too High- 8 Cooling Solutions

3. Inline fan Noise Reduction: The Best Guide so Far