How does fog or smoke machine work?

Fog Machine

As its name suggests, a fog machine, fog generator, or smoke machine emits smoke or fog-like vapor. A fog machine is a tool that is commonly used in professional entertainment, but smaller, more affordable fog machines are becoming more prevalent for personal use as well. In addition to some military applications, fog machines are also used in many industrial, training, and educational settings. FOG is often created through vaporization of proprietary water, glycol, or glycerine-based fluids. In some instances, mineral oil may be atomized to produce fog. Fluids within fog machines (commonly called fog juice) vaporize or atomize as they pass through them. The vapor from the fog machine condenses upon exiting the machine and mixing with the cool outside air. As a result, there is a thick, dense fog.

There are many types of fog machines, but they work in almost the same way. You can find a wide range of prices for fog machines. If you need to use a fog machine for industrial purposes, though you can find them for a bargain, it is probably not worth it.

The most interesting thing is that people use them for their own personal needs as well. Why do such things work? I’m sure you’re wondering. Keep reading to find out!

How does it work

In case you’ve never heard of a fogger machine, it’s basically a device that makes artificial fog – the kind you see in horror movies. You might be wondering how a fog machine works by now, but it’s pretty cool stuff.

A liquid is first heated up in the machine. Vapour is pumped out via an aerosol canister when the liquid becomes vapour. The vapour meets the colder air outside. Your bodies are trying to stay warm, but your brains aren’t- this is how fog forms. 

You can create the fog that you see at dance clubs and in stage productions in three different ways:

  1. You should use a fog machine which vaporizes fog juice
  2. in combination with dry ice
  3. as well as a large group of cigarette smokers

There are several types of fog machines, but the most common is fog juice. Smoke is created by heating fog juice, and there are several types of fog machines. You are doing roughly the same thing when you overheat oil on the stove and create a lot of smoke. Although it tends to get gummy and stink bad, cooking oil has a lot of health benefits. A fog machine uses water mixed with glycerine or glycol.

One thing that is not clear is whether this fog has any effect on the lungs, according to a Seattle Times article. Propylene glycol and tri ethylene glycol are used to create the fog, which is mixed with 20 percent water. According to the information available, it is likely to cause problems for asthmatics, but nothing has been proven definitively for people in general.

To be on the safe side, you can always use dry ice (available at most ice manufactures for a reasonable price — just check in your phone book for “ice” and never handle it with bare hands). By putting dry ice in hot water, a dense fog forms that clings to the ground. As the fog consists of carbon dioxide and water vapor, it is entirely safe.

For theatre productions, fog plays an extremely important role in creating an eerie scene. The performance goes from good to great when you add lights and lasers. You can watch on stage as crackling flashes drain away the light to eliminate all visible light until you are left with a thick, white fog coming from nowhere!

To put things into perspective, let’s look at the big picture. Did you know Michael Jackson had a music video called Thriller? Without fog, how would this song sound? Or imagine Undertaker, the legendary wrestler. If there isn’t a heavy fog obscuring his entrance, how would he appear?

There are different types of fogging machines. Let’s take a look.

Different Types of Fog or smoke machines

There are two types of foggers: heated and chilled. Heat exchangers inside heated machines evaporate the glycol and water solutions. This results in hot vapour. To avoid getting a sunburn, make sure this fog is not too hot to swim in.

It is possible to play around with the fog with some fogger makers’ fans. How awesome is it to be able to create smoke rings or rolling fog? However, if you are wondering whether you should use a chilled or heated machine, we recommend opting for the latter.

There is one more thing you need to know. Not all fog machines produce the same type of fog. Different types of fog have different characteristics. There are machines that produce fog that sticks to the surface, and there are machines that produce fog that scatters.

High vs. low smoke machines

There are two types of fog machines: low foggers and high foggers. These clouds produce dense fog close to the ground, resulting in low-lying conditions. This is great for haunted houses or Halloween parties because it lets bright colours shine through, creating an eerie atmosphere.

The purpose of high fog machines is to create a great deal more fog outdoors. These machines can be used to enhance atmospheric effects or enhance dramatic scenes. Unless someone has a spotlight on them, it’s hard to notice someone standing on stage in more scattered fog.

In addition to being able to use them inside, high fog machines work beautifully outside, too! In terms of visibility, the same rules apply: if you want fog in arm’s reach to be visible, shine a light source near it like a laser or spotlight.

As low fog machines are the most popular, we’ll discuss their different types – dry ice and fluid-based. Let’s get started.

Dry Ice Fog machine

An air-cooled canister of gas is pumped into the atmosphere by dry ice fog machines. The result will be dense but continuously changing cloud formations in your room once this liquid vaporizes.

Dry ice is used as a preservative in this machine, so it is mixed with warm water in order to achieve its intended effect. Sublimated dry ice in the upper atmosphere sublimates, forming a thick fog.


  1. Because of their safety, dry ice fog machines have become so popular. It is a harmless substance. What makes it so? Just open your refrigerator and breathe inside. It’s completely safe unless you want to sleep inside.
  2. Dry ice will become your low-maintenance friend thanks to its long shelf life. The preserves don’t need to be preserved as you can store them for weeks on end without getting spoiled. 

Negative aspects

  1. The volume of dry ice decreases over time despite its long shelf life. So, if you want a thick fog, you’ll need to use a lot of it.
  2. To store dry ice, you’ll have to keep it at a very cold temperature. Frostbites can be very painful if you’re not careful.

Fog machines using fluids

The liquid used in a fluid-based fogger machine is usually liquid nitrogen or glycol. The fog is formed by heating up the mixture. A dense fog is formed when the vapour is released through the nozzle and mixed with cool air.

This kind of fog lingers longer than dry ice fog. The surface won’t stick to it as much, though it is a little warmer. As convection currents carry it upward, it will slowly rise.

In addition, the fog will seem thicker. If you walk by, you will not notice it swirling around. It’s much more fun to add dry ice pellets to your fog to make it even denser.


  1. Fog/ smoke machines that use fluid as opposed to dry ice are usually a bit cheaper since liquid doesn’t go bad like dry ice, and you won’t need a lot of it
  2. It is generally more portable to use liquid-based fog machines than dry ice. There is therefore more fog created per liquid volume.

Negative aspects

  1. Typically, it is harder to clean up liquid fogger machines after they have been used. The chemicals in the liquid may cause the fog to stick. There may even be some stains left behind. If you want to maintain a liquid fogger, you’ll need a thick wallet.
  2. Vapours from liquids might not always be safe. In general, a liquid-based fogger is safe, however if you have an allergy to it, it may not be to your liking.

Frequently Asked Questions

What are the health risks of fog machines?

It depends on what you put in a fog machine whether it’s harmful to your health. Propylene glycol instead of ethylene glycol should be used in fluid-based machines because it is not toxic.

If one has already been irritated by their throat or has respiratory problems, a water-and-glycol mixture would likely not pose any health risks. Stay out of artificial fog if such conditions exist. The fog that forms from dry ice is perfectly safe.

Is it possible to use a fog machine in the house?

A fog machine is absolutely fine to use inside the house however, your house will be covered in fog and some of it may even get trapped in your carpet. As a result, it could damage your carpet if you use a fogging machine.

You should also consult the provider if your home is equipped with a fire alarm system since some detectors could trigger an alarm when exposed to fog.

Is Sanitiser Safe for Use in Fogging Machines?

It is possible to use sanitisers in fogging machines, but we recommend you help a professional with this. Each fogger has a unique amount of sanitizer inside, which is why the concentration will differ.

Additionally, adding sanitiser to a fog machine can be hazardous, especially if it’s flammable or explosive. By inhaling the wrong concentration, the wrong chemistry can damage your lungs.

Is Hydrogen Peroxide appropriate for use in a fogger?

When used indoors, hydrogen peroxide is perfectly safe and effective as a fogger additive. However, if you’d like to verify concentrations before you take them, we recommend you have a professional do it.

It is normally recommended to disinfect at a concentration of 3 percent. It is important to use caution since hydrogen peroxide is a strong oxidiser and may cause other substances to burn.

Is training necessary to use a fogging machine?

Fog machines must be used with training. As long as you aren’t trained, you can use a global licensing body if you’d like to create fog.

Before you use a fogging machine, you should have either informal or formal training. For industrial applications, it’s more important to comply with current safety standards and to stay current with HSE requirements.

Fog creation can be dangerous for others, which is why training is imperative. Prior to using the machine, ensure you are properly trained. Avoid experimenting!

How does a fog machine produce fog?

Fog machines use fluid-based mixtures of water and glycol to produce vapours by heating them up. Upon coming into contact with the colder air outside, the vapour leaves the nozzle of the machine and forms fog.

Fogging machines that use dry ice would vaporize the dry ice and condense the water vapour into thick fog. This also happens with liquid nitrogen.

How could I control the timing of fog machine?

A fog machine can be controlled manually or by a timer. It is important to use a timer for your fog machine if you want to be free to roam around the venue throughout the evening. In an interval setting of 10 to 200 seconds, you can regulate the duration of the fog between 0.5 and 10 seconds. Your guests may be curious to see what lies behind the fog, so you can have it pump back in very heavily just when they start getting curious.


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