Can you grow cannabis without good airflow?

Is it possible to grow marijuana without good air flow?

Yes … It is possible to grow plants without airflow in a sealed environment, however this is no small undertaking. Plant life draws co2 (carbon dioxide) from the atmosphere during photosynthesis and releases oxygen. Without good air flow and ventilation, eventually the plant will use the available carbon dioxide and in effect suffocate. There is a well respected theory that plant life thrives with high levels of carbon dioxide (as were found during the prehistoric eras). Currently CO2 measures roughly 350PPM (parts per million) .. in the age of dinosaurs it was much higher (think about all those big trees which enabled big plant eating reptiles to survive). Growers use specially designed equipment to bring it up to 1500PPM and thus increase plant and flower growth. Logically then it makes sense that keeping plants within a restricted environment where the levels of carbon dioxide gradually diminish and are not replaced is NOT a good idea for optimum bud production.

Does opening and closing the grow door help?

Well only marginally! A half decent extractor (exhaust fan) will extract a significant volume of air every 2 minutes ..

 … so good airflow helps the plant breathe and thrive.

Good air flow helps control heat

By placing your extractor (exhaust fan) at the top of the room it draws out hot air (which rises) and pulls up the cooler air from the bottom of the room. You can control heat issues through other means such as air conditioning  but given the necessity of fresh air to your plants this should be considered as an additional means of heat extraction not the sole means.

Good air flow helps control humidity

A grow room containing living plants will become humid after time as the plants transpire. High humidity is great for young seedlings but very bad for flowering plants. Yes if necessary you can use a dehumidifier to reduce humidity, but again this should be viewed as an additional means.

So in summary:

Is it possible to grow cannabis without good airflow?

Yes .. but its really not to be advised. A good extractor will last for years and be well worth the investment.

This exhaust fan from Hydrofarm is reduced from $144 to $79.95  on It has a reputation for being a solid workhorse, and will quietly (comparatively) keep good airflow for your grow room day after day, year after year.


  • In-line fan
  • Quiet operation
  • Thermally protected
  • AC motor
  • Durable ceramic coating
  • Metal housing
  • Includes mounting brackets and 8′ pre-wired cord!!
  • 2890 RPM 120 volts 60 Hz
  • 20,000 life hours