How Dry Ice Fog Machines Create Thick Fog Effects

Dry ice fog machine are a great way to create an eerie, spooky fog for Halloween haunts, theater productions, concerts, and other events. But how exactly do these machines turn plain old dry ice into billowing clouds of thick fog? Let’s break it down.

What Is Dry Ice?

Dry ice is the solid form of carbon dioxide (CO2). It’s called “dry ice” because it skips the liquid phase and turns directly from a solid to a gas. Dry ice is extremely cold at -109°F (-78°C). When exposed to room temperature air, it undergoes sublimation – meaning it transitions from a solid directly to a gas. This property makes it perfect for fog effects.

How Does a Dry Ice Fog Machine Work?

A dry ice fog machine uses a heating element and air pressure to cause the dry ice to sublimate rapidly. Here are the basic steps:

Loading the Dry Ice

Chunks or pellets of dry ice are loaded into the top chamber of the fog machine. Pellets provide more surface area and faster fog production.

Heating the Chamber

The heating element warms the dry ice chamber to accelerate the sublimation process. However, it doesn’t heat the ice enough to melt it.

Forcing Air Through the Chamber

A powerful fan or compressor blows air through the heated chamber. The warm, high-pressure air causes the dry ice to sublimate faster.

Expelling the Fog

The CO2 gas mixes with the warm air to create a dense fog that pours out of the machine’s output nozzle. Adjustable vents control the fog direction.

Optimizing Thick, Heavy Fog

Several factors affect the density and hang time of the fog:

  • Higher air pressures and temperatures produce thicker, longer-lasting fog.
  • Smaller dry ice chunks have more surface area for faster sublimation.
  • Higher output nozzle positioning prevents the fog from dissipating as quickly.
  • Lower ambient temperatures keep the fog low to the ground longer.
  • Oil- or glycol-based fog juice additives help the fog hang in the air.

Safety Tips

Dry ice fog machines must be handled with care to avoid injuries:

  • Never touch dry ice with bare skin – it can cause instant frostbite. Always wear insulated gloves.
  • Work in a well-ventilated area since carbon dioxide gas is emitted. Avoid breathing it directly.
  • Store dry ice properly – only in insulated coolers, as it sublimates into gas quickly.
  • Supervise operation and keep a safe distance from the fog output.

Create the Perfect Fog Effect

With some experimenting and proper handling, dry ice fog machines can create incredibly thick, long-lasting fog effects perfect for Halloween, theater, concerts, and more. Just be sure to take appropriate safety precautions when operating these chill-inducing machines!

Take your haunted house or stage production to the next level with dense, creeping fog from Applied Physics dry ice fog machines. Contact us today to get specialized advice on optimizing your unique fog effects.


Q: How long does dry ice fog last?

A: With optimal conditions, dry ice fog can last 5-10 minutes in open air before fully dissipating. Enclosed, contained spaces can prolong the effect.

Q: Can you touch dry ice fog?

A: No, you should avoid direct contact and breathing the fog for safety. The extremely cold temps can cause frostbite.

Q: Is dry ice fog toxic?

A: No, but inhaling high concentrations of CO2 gas can be dangerous. Work in a ventilated area and allow the fog to dissipate instead of breathing it directly.

Q: Does dry ice fog set off smoke detectors?

A: Usually not, since it’s water-free vapor and doesn’t scatter light like smoke. But check manufacturer recommendations to be sure.

Q: Does dry ice fog smell?

A: Dry ice itself has no odor, but some fog machine juice additives have a mild scent. Proper ventilation prevents buildup.

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Mahir Company

Mahir Company

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