In case you have yet to see one of them in action, the fog machine is that versatile, one of a kind device used to create an aura of mystery by obscuring what lies beyond it through the emission of smoke. This mystery might be intended to scare, captivate or surprise the audience or participants at an event. It can be used both indoors and outdoors and is a common feature at plays, nightclubs, parties, and Halloween events.
Have you ever wondered what was burning to emit the strange smoke, because as they say, where there is smoke, there is fire? Well, so did we. The first thing we discovered was that the fog was not smoke at all. Rather it is one of the rarely known applications of Chemistry for fun and recreation.
Where Does the Smoke Come from?
There are two basic methods through which the machines produce fog. The first is through turning water and glycol or glycerin-based fluids into vapor. The second is through the atomization of mineral oils.
These processes take place inside the fog machine, after which the vaporized or atomized fluid is released. Upon contact with the cooler outside air, the fluid condenses, resulting in that thick fog we see.
Different fog machines use different approaches to achieve this desired end result. They will be our main area of coverage throughout this article. It is meant to help you understand the rationale behind different fog machines and why anyone would like to have them.
Heated Fog Machines
These are sometimes also known as fluid-based fog machines. They have a heat exchanger heated to about 400˚F before the mineral oil or water solution with glycerin or propylene glycol is propelled through it using an electric pump or inert gas. The solution then vaporizes before it is released from the fog machine.
The Electric Pump Fog Machine
It comprises a fluid reservoir, the electric pump to move the fog fluid along, and the heat exchanger responsible for vaporizing the fluid.
In addition to these standard components, the more advanced ones may have accessories like variable speed pumps through which you can adjust the fog output, timers, or even remote control components.
Gas Propelled Fog Machine
They are commonly referred to as hazers. They utilize some form of inert gas, usually carbon dioxide or nitrogen, to propel the mineral oil or glycol-based fluid through the heat exchanger, where it is vaporized to create the fog. Their fog is thin and gives a haze-like vibe, which is why they are referred to as hazers.
Advanced gas-propelled fog machine models allow you to adjust the fog output by changing the amount of gas used to propel the fluid through them. This is how come they are used in concerts in conjunction with lighting beams to create special effects.
Real Water Vapor Fog
This fog is made by dispersing very fine particles of hot water or steam. Other times it is the water vapor in the air that is condensed. This process is the same as what we see when a freezer door is opened. Water vapor is a non-toxic fog source.
Many modern fog machines rely on some form of water condensation. The hot vapor will float naturally due to its lower density. If you want it closer to the ground level, you may need to involve chillers.
Fluid Based Fog Machines with Chilling modules
These are fog machines meant to mimic fog produced by the dry ice machines. The output is first passed through a cooler unit to lower its temperature relative to its atmosphere so that the fog stays low.
The end result isn’t as light as fog from the dry ice machines since the fluid particles are heavier, especially when chilled.
Because the fog released by heated fog machines is warmer than the surrounding air, it tends to rise as it dissipates. It is thicker in appearance and lingers for a longer time than that produced by dry ice. It does not, however, swirl as easily when someone passes through it.
You can control the fog and manage the effects by increasing or decreasing its ‘on’ time. Heated fog machines also work better with lighting effects than their chilled counterparts because the fog rises, allowing for a more dramatic impact with the different stage lights.
They are also used in aerodynamics for wind testing, training emergency workers, and other industrial applications besides entertainment.
Advantages of Fluid Based Fog Machines
They are available in a wide range of capacities and can produce as many diverse fog styles as you may conjure up. They will not disappoint whether you want it thick or wispy.
They are very convenient when you want to change the fog color using your lights as they are fully exposed to the full glare of the lights and are easily visible.
The fog juice components may cause irritation or allergic reactions from some people, especially the glycol bit. Modern fog machine fluid makers tend to shy away from including it in their formulas.
These fog machines require periodic maintenance because the fog fluid will eventually start to clog the heat exchanger, which affects the fog output, reducing the machine’s efficiency.
Dry Ice or Chilled Fog Machines
These fog makers comprise a large, closed water barrel with a heating element, a hose through which the fog will be delivered, and a mechanism for lowering dry ice into the heated water on cue.
They use dry ice (the solid state of carbon dioxide), liquid nitrogen, or liquid air to create fog. Their kind of fog is usually thick, closer to the ground, and dissipates as it warms up. It tends to be low-lying because it is cooler than the surrounding air, hence heavier.
When dry ice is dropped in very hot water, the fog is created, raising its temperature until it sublimates to a gas state (sublimation is the change of state from solid to gas directly without passing through the liquid state).
The combination of condensing water vapor and gas creates the white fog, which is then directed to where it is needed by a fan placed at the top of the container. Liquid nitrogen is applied in the same way on a chilled fog machine.
Liquid air is the latest fog juice and can be used in place of liquid nitrogen to produce fog. It is made up of nitrogen and oxygen mixed in the ratio of 4:1 respectively and is stored in its liquid form. It is used to create fog in the same manner as liquid nitrogen.
Its advantage over liquid nitrogen is that it can’t lead to asphyxiation because it has oxygen content. The same property, however, also makes it more susceptible to fire than liquid nitrogen. A disadvantage from a safety perspective.
Advantages of Dry Ice Fog Machines
It is non-toxic as it is created using natural elements.
It creates a charming environment resembling the fog floating on a body of water, surrounding your feet and swaying in reaction to your movement. This effect has never been successfully replicated by any other type of fog machine, which is why the dry ice machine remains relevant to date.
It uses up a considerable amount of ice, and since ice loses volume fast, you might be forced to replenish the supply daily. This is exacerbated by the fact that dry ice fog dissipates quickly, meaning you have to keep generating it continuously throughout your event.
It also has minor safety concerns. The first is contact with the skin, which can cause serious damage as it is used at very low temperatures of up to -110˚F; it should be handled with care. It also releases highly concentrated carbon dioxide, which is known to displace oxygen.
This can be dangerous, especially if there are children involved, because they breathe the air closer to the floor where it is most concentrated. The ventilation of the space should be carefully planned when using these fog machines.
Permanent Fog Machine Installations
Theme parks and arena concerts require fog machines capable of producing large volumes of fog or haze continuously for a long time. Some manufacturers accommodate this need by providing larger but less portable versions of their fog machines.
Customizing Your Fog Output
There are two ways you can make your fog output unique and exciting that we need to mention before we proceed so that you do them correctly:
Adjust the Density of the Fog Output
The combination of water to glycerin in the fog fluid determines the thickness of the fog. The less glycerin you have, the lighter the smoke will be. Avoid adding other chemicals unless specified by the manufacturer.
Generating Colored Fog
There is a misconception out there that the color of the fog has something to do with the content of the fog juice. Whereas this may turn out to be true, finding out will cost you a fortune. Adding strange substances like food coloring may lead to irreparable damages to your fog machine. This will also automatically void any warranties or guarantees you might have been enjoying.
The recommended way to make the fog colored that has been tried and tested is to light the cloud of fog with a spotlight of your preferred color. You can change the color as often as you like to customize the theme.
This Donner DFM 500 Fog Machine comes with its own RGB LED lights and wireless remote control. An inbuilt ability to change the fog color without relying on any other lighting source.
Fog Machine Features That You Need to Look Out For
Knowing how the fog machines work is a great start towards operating them. However, when it comes to the actual operation, you will require some help from bits and pieces of the fog machines to set up and survive the event.
Fluid Level Management
If your machine runs out of fog juice while still operating, it risks overheating, which can cause irreversible damage. You need to be in a position where you can always monitor the levels and protect your equipment.
- A lot of modern fog machines come with a fluid level indicator. This will always alert you when your levels are running low so you can replenish in good time. The nature of the event might mean you are attending to other things when this warning goes off, however.
- Auto shut down ability is another important feature you should have an eye out for. It automatically shuts down the machine when the fluid levels are critically low. This protects it from damages, meaning you don’t need to worry about leaving it unsupervised if something important needs your attention.
The Holding Capacity of the Fog Machine
- The fluid tank size has a bearing on how long it will take to empty and how often you need to refill. A large tank is ideal, especially if the event will be prolonged, although it is not always efficient. It is hefty and may be unnecessary baggage for a small and short event.
- Check the fluid consumption rate. It is usually displayed in ml per minute. It is a better figure to use when estimating how long the fog fluid will last
- The size of the chiller box also features at this point. It is good to know how much ice it can hold to estimate if that amount will be sufficient and, if not, how much extra you need to carry.
This is a combination of features that determine how you will set up your fog machine and how early you should start the setup.
- Whether it has a stand or hanging brackets that allow you to mount it somewhere, brackets are especially crucial if you synchronize the fog machine with your lights for that extra creativity.
- If it has a remote control so that you can manage it from a distance, even while mounted, ensuring the fog emission is timely. Some remote controls are wired, and if such is the case, is the length of the wire sufficient?
- How much time does it require to warm up? This should be between 3 to 5 minutes for any decent fog machine.
- What is the wattage rating? The higher the wattage, the more powerful the machine is, and its output will likely be stronger and faster.
- What is the maximum output distance, and how fast does it spray in cubic feet per minute (cfm)?
This Theefun Fog Machine has both wired and wireless remote control functions. The wired console acts as the infrared receiver for the wireless remote. Worth checking out.
Where the Machine Dissipates the Fog
This has a bearing on how you will set up your stage. Some fog machines disperse light fog that will move upwards in the air easily, while other brands like ADJs Mister Cool have specialized in low lying fog machines. Check out their new Mister Cool II with enhanced features.
Smoke Machines and Smoke Detectors
A regular smoke machine should generally not trigger a smoke detector because it doesn’t produce actual smoke, as we mentioned earlier. They do produce fog, though, and if this is too intense, it may trigger the smoke detector.
Care should be taken when using the smoke machine indoors as smoke detectors will disrupt even the most interesting event and send your people scattering. Sometimes it is safer to turn off the smoke detectors when you know you will be using smoke machines on the premises.
To do this safely, you will have to set up alternative warning mechanisms in case a fire starts. It may also not be strictly legal to switch off the smoke detector in certain facilities, and you need to clear with the relevant authorities before such a move.
You need not worry about any of these if the event is outdoors because there are hardly any smoke detectors, and the fog has a lot of real estate to dissipate in.
Smoke machines are not only within the purview of entertainers, club owners, and movie directors. They are now very domestic and are seen across households. The current social distancing measures occasioned by the coronavirus pandemic have also driven people to want to own their own fun without relying on clubs and institutions to provide it. You are not the only one contemplating this move.
Now that you know how they work, don’t hesitate to check out our reviews of the best fog machines with your fresh eyes. You will definitely appreciate that extra punch that comes with adding fog juice to the party.