Location, Location, Location

The location of a dehumidifier in your grow room can make or break its efficacy and efficiency, says Quest Dehumidifiers representative John Pratt. Concentrating your dehumidifiers in one corner of your room will create humidity pockets and could cause them to “fight” each other, Pratt continues, which not only is inefficient but could also hurt your units’ longevity. “You don’t want to try to remove moisture from air that has just had moisture removed from it,” he explains.

Here, Pratt answers common questions about dehumidifier placement to optimize both its efficiency rate and how you can use your dehumidifiers to increase airflow.

1. How does the location of my dehumidifier in my grow room affect my environment?

Having a dehumidifier in the right place in a grow space can help a grow environment tremendously. Adversely, a dehumidifier in the wrong place can result in little to no effect. In the wrong position, a dehumidifier can struggle because of things like cold air from an AC, poor spacing of dehumidifiers, not enough room from the wall, too far from the plants (if the room is very tall).

2. What is the optimal location to reduce humidity?

This depends on how many dehumidifiers you need. If only one is needed, centrally located in the room, above or next to the lights is generally the best placement. There are variables that affect placement, such as room height and airflow. For example, when a room has a low ceiling you might not be able to hang your dehumidifier. In this case, we might recommend a floor placement or under a table. We recommend reaching out to us or a licensed HVAC professional to ensure correct placement.

3. What is the optimal location to increase airflow?

Place your dehumidifier at the recommended distance away from the wall to eliminate “choking” of the machine. Also, placing it away from direct flow from an air conditioner or heater will help with airflow.

Each dehumidifier has different wall spacing guidelines. Make sure to reference the owner’s manual if you plan to place near a wall. For example, Quest’s 5 Series dehumidifiers should be a foot from the wall.

4. What advantages do different potential locations offer?

There are multiple options for placement. The decision comes down to the grower in each individual space. Every grow room is slightly different.

Some growers prefer to have them under their tables. This is perfectly fine. They will perform well as long as there are no obstructions to the supply and return openings.

Some growers do not have the room to hang their dehumidifiers in the middle of a room and put them at the end instead. This is also fine as long as they are not near the AC and not restricted.

Lastly, there are growers that simply do not have any space for more equipment and duct their dehumidifier from outside the room. This is a great solution for people who have limited space. The only thing to avoid is running the duct too long. You want to keep the duct length under 30 feet.

5. If multiple units are required in one room, how should growers space them out to maximize efficiency?

The best way to place multiple units is to space them out evenly throughout the room. This eliminates the possibility of humid pockets.

6. How many fans should cultivators add to maximize airflow and dehumidifier efficiency?

A: This is grower preference, but we recommend as many as you can without damaging the plants. More airflow the better is our recommendation; just not at the cost of the health of the plant. You want to see plants “dancing” from the airflow but you don’t want to see severe bending of the entire stalk.

Editor’s note: This Q&A has been edited for length and clarity.

_{Photo at top: A grow room with two Quest dehumidifiers. This company was forced to put two units next to each other, but added more fans to increase airflow and reduce the risk of humidity pockets.}