Do Greenhouses Need Ventilation?

Recall the biology class where you learn that plants need a continuous supply of carbon dioxide (CO2) in addition to sunlight to prepare their food via a process called “photosynthesis.”

It’s a no brainer when thinking of plants growing outside, in the open air where 300-500ppm CO2 is present. But have you ever wondered about the greenhouses? 

Inside a greenhouse, the air doesn’t circulate naturally, making the breathing process difficult for plants. Thus, how can you manage this problem? A simple answer to this question is “Greenhouse Ventilation!” 

Does A Greenhouse Need Ventilation?

Who thought that this would even be a question! Yes, the greenhouses surely need ventilation to circulate the fresh air. Regular air exchange proves to be beneficial for the plant’s growth and thriving.

There can be plenty of reasons behind this improved growth and effective photosynthesis. Some of which includes:

  • Ventilation improves the temperature inside.
  • It regulates the humidity. 
  • It provides enough CO2.

4 Reasons Why your Greenhouse Needs Effective Ventilation:

Greenhouse ventilation is as important as the greenhouse itself!

Without much airflow, the greenhouse will lose its bloom, and the crops end up dying. Here are 4 reasons why greenhouse ventilation is a must!

1. The temperature in Range:

A greenhouse is meant to provide suitable heat to plants, which keeps them growing at their full. But what if the heat traps for so long?

The plants and crops will end up being the victim of such high heat and eventually die. Thus, proper ventilation at the right spot helps improve the heat loss so that the plants can do well.


2. Adjusts Humidity:

Plants usually transpire water, which needs to be evaporated. A fully-sealed greenhouse can fall victim to its own humidity if not ventilated.

Thus, proper ventilation will remove extra humidity from the inside environment to prevent fungus and mold growth. 

Here’s a quick look out for the balance between the heat and humidity that works best for a greenhouse!

Degrees CentigradeHumidity

3. Enough Carbon Dioxide:

Carbon Dioxide plays the same role as oxygen plays for human beings for a plant to carry out photosynthesis.

Thus, to prepare the glucose, a portion of food for plants, enough carbon dioxide is a must- provided by suitable ventilation.

4. No More Disease Infestation:

Microbes and pests find the cozy temperature and humid environment suitable to grow and breed!

To save your hard-earned yield, ensure the proper ventilation to eradicate the pests and microbes.

What type of Ventilation do You Need?

There are mainly two basic Greenhouse Ventilation types named Natural and Mechanical- each having its own merits and demerits.

Here is a quick overview to let you choose the ideal one for your greenhouse.

  • Natural or Passive Ventilation:

As the name states, it’s completely natural! Neither has it used the fans nor the heating systems. It works on the simple principle of Thermal Buoyancy- the heat rises as it gets warmed and maintains the airflow. A series of roof vents and on the walls can complete the overall setup for this type.

  • Mechanical or Active Ventilation:

In this type, you’ll need to utilize the mechanical power in terms of fans to maintain the proper airflow.

This way, not only you’ll have much more controlled heat and humidity but control in turning the system on and off. On the other hand, the mechanical system might cost you a little extra!

Experts suggest, “It’s cost-saving to have the natural ventilation, but it’s life-saving to have the mechanical ventilation in place as well.”


The plant needs to breathe and respire to carry out photosynthesis, which keeps them survive by preparing their food through carbon dioxide and sunlight.

But improper airflow can hinder the process inside the greenhouse, leading towards the wilting of plants.

Setting up a proper ventilation system and devising strategic ventilation points in active and passive ventilation is a must-have thing to enhance the crops’ yields.

It is suggested to at least utilize 20% of the greenhouse’s area for ventilation purposes. For example, if you own the 300ft of the greenhouse, devote the 60 sq. ft. to ventilation on the roof and sides.

Thus, by blending the natural thermal buoyancy with the mechanical fan system, you can maintain a proper heating and cooling environment, which leads to adequate ventilation. Proper ventilation eventually equals productive growth!

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