KDomingo owns a ground fogger and has experimented with many different fog techniques.
Techniques for Creating Ground Fog
Ground fog can be easily achieved by understanding how fog works within its environment. This article will explain how to achieve a low-lying fog effect, along with providing suggestions to further increase the quality of the effect. I will not be going into too much detail about the different types of fog machines or fluids, because that is a lot of content, but I will introduce the machine and fog juice that I use.
This article is based on my experiences, and the opinions expressed are my own. These techniques work for me, and I hope they work for you!
About My Fog Machine
The fog machine I'm using is a 400-watt ground fogger. It's called a "ground fogger" because, unlike normal fog machines, it has an ice compartment, which I will talk more about below. This fog machine isn't the exact product that I'm using in the example videos and pictures in this article, but it's similar to mine: It's a 400-watt fog machine with an identical structure, and it should produce the same results.
Do You Have to Use a Ground Fogger?
No, you do not need a ground fogger. Any type of fog machine will work.
What Does the Ice Compartment Do?
If you are curious, the diagram above shows the structure of a fog machine with an ice compartment and how it works. You may not be able to see it, but there is a partition separating the area before the ice compartment and the exiting chamber, so the fog must travel through the compartment before leaving the machine.
About the Fog Juice
I usually use this High-Density Bog Fog juice, but I needed some fog juice for a party and didn't have time to wait for delivery. So, I bought the one displayed in my pictures at a local store. It works pretty well, but it isn't as thick and doesn't last as long as the Bog Fog juice.
Is High-Density Fluid Required?
You don't need to use high-density fog juice, but for ground fog, I recommend it.
What Controls the Height of the Fog?
The two main factors that affect how low or high your fog will be are the temperature of the fog and the temperature of the surrounding area. Basically, think of it like this:
- The cooler your fog is, the lower it will stay.
- The cooler your surroundings are, the higher your fog will rise.
Why? There are scientific reasons involving the density of air, but for simplicity, hot air rises and cool air sinks. So, if the fog is significantly cooler than its surroundings, it will stay lower for longer.
The Secret to Low-Lying Fog: Ice
Low-lying fog is something many people try to achieve. The best way to do this is to cool the fog down by having it travel through ice. As we discussed earlier, some fog machines, such as mine, have a small ice compartment to facilitate this. Also, having denser fog juice is important for low-lying fog (but not absolutely required).
Videos for Comparison
Below, I have included two videos demonstrating my fog machine with and without ice. Notice how heavy the cold fog is compared to the light, un-iced fog. The colder fog stays low and spreads across the floor. The fog without ice goes straight up and then begins to spread.
As time goes on, the colder fog will rise about 4–5 feet and dissipate, while the hotter fog will try to fill the room and linger a lot longer than the colder fog.
What If My Machine Doesn't Have an Ice Compartment?
If you are using a fog machine that doesn't have a cooling compartment, or you want to cool your fog even more, you can create a fog chiller. There are many simple ways to create a chiller for your fog machine. Below, we'll go over two videos demonstrating different methods.
How to Make a Fog Chiller: Method 1
The video above demonstrates how simple it is to make a fog chiller. In this chiller (and in most chillers), notice that there are three things to consider:
- How the fog machine will connect to the chiller.
- The structure of the chilling area.
- Where the fog will exit.
1. The Connection
As the video creator demonstrates, connecting your fog machine to the chiller can be as simple as cutting a hole in the container and placing your fog machine up against it. You can also use other materials to create a better seal/connection between the fog machine and chiller.
2. The Structure
When designing the chilling area, keep in mind that you want to chill your fog as much as you can. You can keep it simple, like in the video, but if you have some extra supplies, I advise that you add some obstructions for the fog. That way, the fog will have to travel around—instead of being able to go straight through—the fog chiller. Basically, you want to make it stay in the chiller longer, which will result in colder, lower fog.
3. The Exit Hole
Again, in the video, you can see that the chiller has a wide exit hole. The size shown is good for a 400-watt fog machine. If your machine has a higher wattage, you may want a bigger exit hole. This will help spread the fog and keep it low.
If the exit isn't big enough, the fog will be forced out and will rise a few feet. I have seen people compensate by cutting a hole in a plastic bag or a box to fit the exit hole and then attaching it to the chiller, allowing the fog to spread out evenly when it exits the box or bag.
Fog Chiller: Method 2
Above is another video that demonstrates a pretty inexpensive fog chiller setup with the three pieces described above:
- A sealed connection from the fog machine to the entrance of the chiller.
- A chiller the fog must travel around.
- A wide exit.
This is a good model to follow if you decide to make your own chiller for your machine. I like this design because both the chiller and the tube that the fog travels through are sealed. So, even when the ice melts, the water will stay in the chiller, creating iced water.
More Tips and Suggestions for Ground Fog
Here are two more strategies for creating a high-quality—yet low-lying—fog effect.
Use Dry Ice
If you can afford it, I recommend using dry ice because it's colder than regular ice made from water—and, more importantly, there's no cleaning required after it melts. Dry ice undergoes sublimation, which means it melts into a gas, not a liquid. Also, instead of using dry ice exclusively, you can add it to regular ice to slow down the melting rate of both ices.
The disadvantage to using dry ice, besides the expense, is that you have to use it the day you buy it; otherwise, it will melt—unless you happen to have a cooler that is capable of achieving a temperature of -100°F. If you didn't know, the normal household kitchen refrigerator can barely go below 0°F. With that being said, another disadvantage is handling it. You need thick gloves or you might suffer from a dry ice "burn" because of how cold it is.
Warm Up the Surroundings
Another way to help keep the fog low is to turn on the heater before using your fog machine (if you are inside a building or room where you can control the temperature). The greater the contrast between the temperature of the surroundings and the fog, the lower your fog will be.
Steve on September 08, 2018:
Low lying fog is not working in bar rooms due to drafts. What can we do to fix this?
Andry Rakotomalala on September 08, 2017:
Dude, this was perfect! Thanks so much for your wealth of knowledge and for sharing it!