Proper humidity levels are essential for maintaining optimal air quality in a grow room, but efficiently monitoring and managing these levels can be challenging.

When designing and engineering an indoor garden, it’s crucial to consider the amount of moisture that will build up as a result of plant transpiration, as too much moisture can dramatically impact crop production and quality. Molds such as powdery mildew could ruin your entire harvest.

Investing in a high-quality dehumidifier can help ensure optimal humidity levels, but first, proper dehumidifier size must be determined; this will depend on your grow room’s specific needs and requirements.

Evaluating Your Grow Room’s Dehumidification Needs

Indoor Growhouse BlogTo properly size a dehumidifier for your indoor grow house, first consider the specific environment you’ll be working in and the daily operations you’ll be running. For example:

  • How much water are you giving your plants every day?
  • Are you running an air conditioner for temperature management? If so, what is its dehumidification rating? Check your particular setup; it should indicate how many pints of water it removes from the air per day.
  • Are you using CO2 in your grow room?

Below are some key factors to keep in mind when determining the ideal size for your grow room dehumidifier:

Gallons Per Day

To determine how much moisture buildup will occur in your grow room, work out a rough estimate of the number of plants in your space and how much water they’ll receive. For example, 30 plants that receive 1 gallon of water per plant per day means a water input of 30 gallons.

Each gallon holds 8 pints, which would be a total of 240 pints of water per day. This is converted into pounds per hour; 1 pint is equal to approximately 1 pound of moisture. Therefore, in this example, 240 pints of water would equal 240 pounds of water per day. This means 10 pounds of moisture per hour is being removed over 24 hours. 

Plants transpire roughly 97% of the water they’re given, so pinpointing the amount of watering you plan to do is an easy way to approximate how much moisture will need to be removed each day.

Temperature Range

Different types of grow rooms and plants will require different temperature ranges to thrive, and different growing cycles will require different temperature ranges.

For instance, a cloning room may start out at 75 °F degrees, while a flowering room for the same plant may be held at 78-80 °F. And a drying and curing room may see temperatures closer to 65°F degrees.  


Evaluating your grow room

Dehumidifier Sizing

Dehumidifier solutions are sized based on their total moisture removal capacity. The capacity is rated in pints of moisture removed per 24-hour period — a 30-pint dehumidifier model, for example, removes 30 pints of moisture every day.

Again, the pints per day can be converted to pounds per day or per hour with the understanding that 1 pint equals approximately 1 pound of moisture.

Additional Environmental Factors

Also consider the type of media being used for your grow room: What will the plants be raised in? Will they be potted in soil and watered? Will they be provided with a different substrate? Will they be constantly irrigated? Transpiration rates will vary depending on your specific drainage and watering systems.

It’s also key to consider:

  • If you are using ventilation and your climate is generally humid; if so, factor in an additional 10 pints
  • If humans will spend time in the grow room space; if so, factor in an additional 5 pints
  • If the space includes multiple doors/windows; if so, factor in an additional 5 pints

3D book growhouseGrow Room Dehumidifier Solutions From DCA

Ready to learn more about indoor farming and moisture management? Check out our free eBook, “Indoor Farming: Ensuring High Yield, High Quality Crops with Custom Dehumidification and Air Quality Systems.”

Or, to discuss how we can help with your specific grow room needs, reach out to the team today. The experts at Dehumidifier Corp. of America (DCA) are on hand to answer any questions you may have.

Topics: Dehumidifiers, Indoor growhouse dehumidification