Fogger or Mister? Which One Should I Use?

Welcome to the Fogger and Mister Buying Guide. They look similar, they operate similarly, and they even serve a similar purpose, but the subtle differences can make all the difference in your application. The purpose of this guide is to explain what foggers and misters are, their differences, and when and how each might be used. Our goal is to help you choose the one best suited to your needs.

Pictured: DIG Misting Nozzle on Barb                                                                             Pictured: DIG EXL Series Fogger

What are Foggers and Misters?

Foggers and misters are watering devices that focus primarily on reducing temperatures and controlling humidity levels, instead of soil saturation. They produce water at lower volumes but operate at higher pressures (PSI). The low water volume combined with the high pressure creates a mist/fog effect. Whereas drip emitters and sprinklers are meant to wet the soil for plant uptake.

The small droplets of water allow for quick evaporation which cools the air and creates more humidity. Although these devices are popular in nurseries and greenhouses, they can also be used in a wide range of applications.

Pictured: DIG Pot and Basket Mister with Stake                                                                                        Pictured: DIG Misting Nozzle on Barb                                

What is the difference between Foggers and Misters?

Think about the difference between a foggy morning versus a light mist in the air. In the mist, you may feel a couple of light drops and soon enough, you may even be lightly coated in water. Fog, however, you can walk through and can feel the temperature difference and possibly a humidity change, but you will not feel as wet as you would walking through the mist. 

One of, if not the most important aspect of these watering devices is the difference in the water droplet size. The unit of measurement used to determine water droplet size is a micron. A micron is defined as 1 millionth of a meter or 1 thousandth of a millimeter (pretty small!). 

For a size comparison, a single human hair is about 0.004 inches in diameter or about 100 microns. For volume comparison, if you were to break one gallon of water into water droplets, let’s say 50-micron droplets, this would produce about 68 billion droplets of fog.

Fog particles are generally considered to be 50 microns or less (0.002 inches) in diameter. Whereas, mist droplets consist of larger particles from 50 to 100 microns (.002 - .004 inches) in diameter. 

Here is a quick table of the differences between misters and foggers:

When should I use each, or are there times when either could be used?

Due to water droplet size, misters and foggers can be used in different applications for more precise results. There are applications specific to foggers, just as there are applications specific to misters. However, there are also applications when either would be suitable. 

One of the most distinct differences in the recommended applications between foggers and misters is where they are used. Foggers are predominantly recommended for indoor use. Misters, however, are recommended predominantly for outdoor use. That being said, we find every system is unique, and there will always be exceptions to every rule.

When and why you would use foggers:

For many reasons, fog is a fantastic alternative to mist in specific applications including germination and propagation in greenhouses. This is because fog can provide a more uniform wetting across the plants in your greenhouse without over-saturation of the soil, thus reducing disease and fungal growth. Fog can achieve deeper penetration into the leaves and oftentimes is more efficient than misting. The real purpose of a greenhouse is basically to create a controlled environment for optimal plant growth and development; in this regard, foggers are also excellent for cooling the environment.

Foggers are recommended for plants that are susceptible to root disease, propagation of seeds, and non-rooted cuttings. This is because foggers are better for controlling and building humidity, and keeping the root area and leaves moist, without completely saturating the soil.

Foggers are used in overhead applications, generally mounted on or hanging from the overhead supply line of a greenhouse, nursery, or hoop house.

Here are some sample uses of Foggers in various applications:

In Greenhouse applications, this includes: Evaporative Cooling, Propagation, Pesticide Application, and Fungicide Application
Orchard: Evaporative Cooling, Foliar Fertigation, Pesticide Application, and Fungicide Application

When and why you would use misters:

Pictured: DIG Ocean Breeze Kit                                                                                                                                   Pictured: DIG Ocean Breeze Kit

Mist is often used for temperature control in outdoor settings such as decks, patios, pools, and animal shelters/enclosures, as well as some applications of watering. The small droplets are perfect for delicate plant foliage, such as ferns or some ground cover, where traditional sprinklers may be too damaging to the plant structure.  

One application that specifically misters are recommended for is the propagation of rooted cuttings. This is because mist covers the leaves and stems to remain consistently moist, but not soaked. 

Misters, when used for cooling purposes, are recommended to be mounted higher up, around 8-12 feet overhead for optimal results. It is also recommended to install the mister nozzle at a 90-120 degree angle to the ground. Ideally, the mist is meant to evaporate before ever hitting the ground. 

Misting plants can be done overhead as previously mentioned, or raised above the plant canopy on a riser and is often recommended to be installed at a 70-degree angle, or upright so the mist can lightly fall onto the plants before evaporation occurs. 

For densely planted areas or for a maximum cooling effect, it is recommended to place the misters close together for full, overlapping, and even coverage. They are not recommended to be used in windy areas, as the small-sized droplets can be easily dispersed in the air, even under low-to-moderate wind conditions, the wind can negatively affect uniformity and performance. 

One of the main advantages of the misters is that a relatively large number can operate at once. They are recommended to be spaced every 2-4 feet for optimal coverage. As a note, you’ll want to confirm the tubing or mainline in your system can handle the volume of water (GPH) you will be using, as that will determine the limitations of how many misters can be installed on one line.

Times when either could be used:

Pictured: Antelco Vari-Jet Mister on Flex Assembly                                                                    Pictured: DIG Fogger on the barbed elbow

Misters and foggers can be used in pots, hanging baskets, and anywhere that overhead watering is recommended. These are great for plants that require constant moisture or a specific level of humidity. They are both available in barbed or threaded connections making them compatible with a variety of different systems.

How to choose a fogger or mister?

There are a couple of factors to consider when you are looking for a fogger or mister; including the purpose of the device, the droplet size, the volume of water, and the PSI range.

First, you’ll want to determine based on your application if you are looking for temperature control using evaporation (misting) or if you are looking for humidity control (fog). 

Next, you’ll want to consider the droplet size (measured in microns) that best suits your needs. Again, you’ll want to use the application to best determine if you want larger droplets or smaller droplets. Are you wanting to water the plants, cool the air, or control humidity? Different droplet sizes correspond with different effects. 

Third, you’ll want to consider the volume of water needed. If you are going to be cooling an area, water volume typically is not a huge concern, as it will evaporate before hitting the ground. However, if you will be watering the plants or controlling levels of humidity, the volume of water (gallons per hour) that is produced by the watering device will matter. 

The last factor to consider is pressure (PSI). Many foggers and misters operate at a higher pressure range in order to achieve the performance desired. The higher pressures are what create the fog or mist-like effects. Whether you have an existing system or will be installing a new system, you’ll want to ensure you can provide the necessary pressure to operate the devices.