Irrespective of the amount of decorating your next concert or Halloween haunt will involve, there is one crucial mood-setting detail that will set your spook alley or yard apart from the rest. I will not keep you guessing.
If you want to create the spookiest Halloween mood or spruce up your concert stage, a simple element that can achieve this goal is creating some dense fog. Fog can not only make a huge difference, but it is also easy to generate.
In this article, we will explain to you everything you need to know about fog machines. From how they work, to their common uses, to some FAQs and tips, and more. If you are looking to learn more about fog machines, then you have come to the right place. These are very flexible machines and you would be surprised how you might have a use for them that you never thought of.
So read on to get started and learn more.
In This Article You Will Learn...
What Is A Fog Machine?
A fog machine also called a smoke machine, or fog generator is a device used to emit a dense or opaque vapor quite similar to smoke or fog. Artificial fog or smoke has long been a part of a variety of professional entertainment applications; however, smaller and more economical fog machines are increasing in popularity for personal use. They are no longer reserved for professionals, and you will find that there are a lot of affordable options out there.
There are plenty of training, industrial and military applications for fog machines as well. Moreover, a lot of warehouse and production units have these devices installed to keep out bugs and to regulate humidity.
In most cases, fog is created through vaporization of water and glycerin-based or glycol-based fluids or via atomization of mineral oils. This liquid (often known colloquially as fog juice) atomizes or vaporizes in the fog machine. On exiting the fog machine, the vapor mixes with colder outside air and condenses, creating a thick visible fog.
There are several ways of creating a unique ambiance or mood for different kinds of events you might be having. A fog machine is a great and simple way to produce fog or mist in the air, enhancing all types of affairs, from haunted houses and Halloween parties to theatrical productions, rock concerts, and dance parties.
Fog machines are available in different sizes and have varied levels of mist or fog output. The kind of fog machine that best meets your needs will depend on the size of the area that you want to make foggy. Of course, the more extensive your needs the more powerful fog machine you will probably need. Read on to find out more about the common applications of fog machines.
How Fog Machines Work
Fog machines are quite simple to use. While you don’t necessarily need to know the inner workings of a fog machine to get some use out of it, it can still be quite interesting to learn the science involved.
A fog machine is not a very complicated machine. Essentially the device is designed to pump fog juice or fog liquid from a reservoir to a heat exchanger. Then the fluid is heated and turns into vapor.
In most cases, there are five parts in a fog machine which make it work. These are the heat exchanger, pump, nozzle, fog machine fluid and remote control (found on most models).
The fog juice or fluid goes into the reservoir. It is forced via a heat exchanger using a high-pressure pump. Heat exchangers on most fog machines can heat up to 450 degrees Fahrenheit.
That turns the fluid into a vapor. The vapor moves through the fog machine's nozzle and out into the atmosphere. As soon as the gas makes contact with the colder air outside, it condenses into fog or smoke.
A piston or pressure pump delivers the fog juice or liquid from the reservoir to the heat exchanger. In case you hear any sound during the operation of a fog machine, it is usually the pump working. Fog machines pumps are most likely the loudest parts of the machine.
A heat exchanger is a metal block that has a heating mechanism built inside. A thermostat regulates the temperature inside. The heated liquid travels to the machine’s nozzle in vapor form.
If you compare different models of fog machines, you will notice the term “watts." Fog machines with higher watts of power can produce more fog. That is why it is crucial you go for a top wattage machine as it will have fewer re-heat cycles because of the sturdiness of the heat exchanger.
The nozzle of a fog machine is usually brass. It has a tiny opening or hole that emits vapor under pressure.
During operation, both the opening and nozzle can become extremely hot. Therefore, do not place anything flammable near it or touch it. A majority of modern fog machines come with remote controls. The remote has a single button and operation is very simple.
All you have to do is hold down this button to release mist and stop the fog by releasing the button. A remote control with an automatic timer is a great option. You can set the timer and control when and how much fog comes out along with the duration of the release. This timer remote may come in handy if you need a specific amount of smoke to time it along with music, a stage show, or a different kind of presentation.
So there you have it, fog machines aren’t overly complicated. However, there are many important differences that make some fog machines function differently from others. The next section will examine these different types.
Types of Fog Machine
There are many types of fog machines available on the market with different wattages, sizes, warm up times, and output. We will consider the main types of fog machines in this section. If you are in the market to purchase a new fog machine, this section can help you understand the distinctions between each, and help you determine which would meet your needs.
Heated Fog Machines
A heated fog machine uses either an electric pump or inert gas to propel a mixture of glycol, or glycerin, mineral oil and water into a heat exchanger. The mixture vaporizes in the heat exchanger.
The pump machine is the most commonly used type of heated fog machine. The most basic version of a pump machine comes with a liquid reservoir and has an electric pump that moves the liquid and a heat exchanger to vaporize the liquid.
On the other hand, sophisticated models often have many different features, such as a variable speed pump that controls the fog output, timer module or components for remote monitoring and operation of the fog machine.
A few manufacturers produce fluids and other accessories that, when used with a standard heated pump machine, develop fog or mist effects very similar to those created by chilled fog machines.
A gas-propelled fog machine uses an inert gas (mostly nitrogen or CO2) to drive either glycol-based fluids or mineral oil into the heat exchanger vaporizing it into particles, which creates a fog. Some models of modern gas-propelled fog machines offer control over fog output by changing the gas volume.
Chilled Fog Machines
A refrigerated fog machine is designed to generate thick, opaque fog clouds that stay close to the floor and slowly dissipate while rising. The shadows of the fog are usually created using liquid nitrogen, dry ice or recently moist air. Dry Ice effects are produced by slowly heating water until it reaches the boiling point.
A suitably large container is used for this purpose (for instance: a 50-gallon drum with heating coils inside). Then a couple of pieces of dry ice are placed inside. As carbon dioxide is in a gaseous state at standard pressure and temperature, the ice sublimates instantly and produces gas.
The condensation of water vapor creates a thick white fog. One or more fans placed at the top of the water container to direct this fog where it is required. In many cases, liquid nitrogen is used to generate a low-lying fog or mist effects in a way quite similar to dry ice. This low-lying or ground fog creates a very interesting effect that is helpful in many stage shows and concerts.
For this purpose, a machine is used to heat water to the boiling point, producing steam and raising the humidity level in a closed container. As soon as nitrogen pumps into the water container, the moisture quickly condenses and creates a thick and white fog.
Fans are used to direct the mist where needed. The fog chiller often creates a rolling fog that tends to lie close to the ground.
Moreover, liquid air can be used as an alternative to liquid nitrogen to generate the low-lying fog effect, which looks spectacular. The moist atmosphere from the fog machine around you is made up of nitrogen and oxygen combined in a precise ratio of 21% oxygen and 79% nitrogen. The liquid rests in an insulated cylinder.
The rate of oxygen to nitrogen is the same as found in atmospheric air. Liquid air is fabricated by the process of liquefaction. Atmospheric air is compressed, cooled and expanded - this process repeats until the air becomes a liquid.
The main advantage of using liquid air instead of liquid nitrogen is it poses no asphyxiation risk, as it has oxygen in it. However there is also a downside; moist air supports combustion, while liquid nitrogen restricts it.
Haze Machines
A haze machine also called a haze generator, or just a hazer is designed to create homogeneous and unobtrusive clouds in the air. The device mainly helps make the light beams visible or produce a subtle diffusion. Different from a theatrical fog that is often intended to be opaque or dense, haze is usually quite delicate and light.
These unique properties of haze allow a venue, such as a concert stage, to be filled with it before or during the event without having to create an overtly distracting fog cloud. Also, haze has a considerably longer persistence compared to traditional theatrical fog. Because the fog itself is not as overpowering, it works very well to amplify and exaggerate lighting effects and lasers.
A conventional fog would stay suspended in the air for only a few minutes, while a typical haze effect used in the same space volume could last from one hour to several hours. The exact duration will depend on the venue size and amount of ventilation.
Fluids used in a haze machine to create the effects are water or oil-based. A majority of oil-based liquids use mineral oil bases; on the other hand, water-based fluids tend to use a glycerol or propylene glycol base. While both fluid formulations are known as haze fluid, keep in mind the different fluid formulations are neither interchangeable nor compatible.
Propylene water/glycol haze solution is sometimes called "water-based haze" to avoid confusion or ambiguity. Describing this solution as "glycol" may cause stagehands or other professionals to use antifreeze, which often contains ethylene glycol and you should not use it for this specific purpose.
These were the three main types of fog machines. If you are looking to purchase a fog machine yourself, try to pick the one with the features that best match your needs. They all produce noticeably different types of fog, so adequate research is necessary to ensure that you get exactly the effect that you are searching for.
Types of Fog Effects
The above section outlined the three main types of fog machine. However, depending on the type of fog juice (more on this below) and fog machine you are using, there are actually many different types of fog effects that you can achieve.
This section will outline some of the more popular fog effects.
Low-Lying Fog
A ground fog machine can be used to create a low-lying fog. Low-lying fog is specially formulated to stay close to the ground and cover the floor in a cloud-like effect. Its usages will be covered more in detail below, but it is especially popular at nightclubs, weddings, and on stage at performances.
Low-lying fog can be created to last long and envelope the ground in fog, or to quickly dissipate for a more temporary effect. Its usages are plentiful and they really depend on your level of creativity.
Haze
Haze is the considered the lightest, most transparent type of fog machine effect. It is a very light fog, and is generally used to accentuate other effects, such as lighting. You might not even notice the haze that much, but the effect it has on amplifying lasers and LED lights is very noticeable.
Haze is very popular at concerts and nightclubs (more on that below).
Medium Density Fog
Next up is medium density fog. This fog is still meant to be transparent, but is noticeably thicker than haze. This fog is meant to be more noticeable, while still allowing transparency to keep the focus on the sporting events, stage plays, or anywhere it is used.
Similar to haze, it is also quite often used to amplify lighting effects.
High Density Fog
High density fog is meant to be the least transparent type of fog. It is often used in special effects, to limit visibility in certain situations, or in theater and concert production. High density fog is also useful for fogging an outdoor area where the wind tends to blow away the fog over time.
Typically, the denser the fog, the longer it will last in a room. So high density fog is also useful if you intend on maximizing the amount of fog and also the amount of time that a fog effect will last.
Fog Burst
You have probably seen this fog effect at concerts, sports venues, or many performances that were looking to add a quick, dramatic effect. The fog burst is a very high-density, fast burst of fog that shoots out of a fog machine all at once. Often, the fog is shot into the air in an effect that mimics that of a geyser.
This effect is often used to amplify a situation and add an additional level of intensity. You might have seen it when a sports team takes the field or when a particularly exciting part of a song is played at a concert.
As you can see from this section, many different types of fog are created with fog machines. This makes their applications very wide, and the next section will dive deeper into the various popular uses of fog machines.
Uses of Fog Machines
There are many different types of fog machines with many different technical features, and as such there have become many different uses for fog machines. Fog machines are used extensively in concerts, theaters and for various industrial purposes. This section will outline some of the most popular usages of fog machines, as well as some less popular ways that might surprise you.
If you are unsure whether or not you can find use for a fog machine, this section may be of inspiration to you.
Theaters
Fog machines are used in shows and help create a specific feeling or mood for different theatrical moments. They are also used in a variety of plays like A Christmas Carol, Dracula, and MacBeth.
Theatrical fog and smoke are indispensable if you want to create different types of visible and mid-air laser effects to keep your audiences entertained.
Fog machines are also especially helpful in magic shows and performances. Not only does the fog create a special, mystical atmosphere to accompany the show, the fog can actually be helpful in hiding key details and assisting the magician with their act. Many magicians have found very creative usages for fog, but you would be hard pressed to find out what these secrets are.
Liquid carbon dioxide, (usually kept in compressed cylinders), is also often used in combination with fog machines to create a "low-lying" fog effect in theatrical performances. You can use the fog machine to create a dense, thick fog that hovers within a couple of feet of the floor. As this mist slowly warms or agitates, it starts rising and dissipating. This type of fog is used in many stage shows, musicals, plays, and more.
A lot of theatrical fog fluid manufacturers have recently created specially formulated mixtures that can mix with carbon dioxide. They provide more consistent and thicker fog effects. The duration of the fog effect usually depends on the heating cycle of fog machines as well as the consumption rate of carbon dioxide.
Concerts
Fog machines are popular in music concerts. Many bands maintain their own sound systems, fog machines, and even lights. According to many musicians, fog is essential. Also, if a group only has a fog machine, it can do the trick as a majority of venues and clubs have lights. Fog is perfect if you are looking to create the right atmosphere or ambiance for a musical performance.
Many musicians also prefer buying scented fog because the crowd tends to enjoy it more compared to standard unscented mist. There are different versions of scented fog such as vanilla and musk.
A very popular effect for concerts is created using a haze machine. Haze machines tend to create fog that is not as thick, and also lasts longer. This haze also amplifies the lighting effects of lasers or LED lights, and makes the light more distinct and noticeable. It creates a very interesting effect, similar to beams of light cutting across a room. If you witness a laser show at a concert, there is probably a haze machine involved.
Nightclubs
Due to the refractive and reflective qualities of the fog produced by many fog machines, they are extensively used in many nightclubs and various other entertainment sites to improve or augment the effects of laser and lighting arrangements. Haze machines are the most widely used type of fog machine in nightclubs.
Another application for fog machines in night clubs are ground foggers or low-lying fog machine effects. Some nightclubs will use a ground fogger to cover the dance floor or the stage in ground fog, to create a mystical effect for everyone involved.
Special Effects
A major application of fog machines is in special effects. Whether it be a major production, a stage show, or even a home-made production, fog effects are useful and accessible. Fog effects have long since been used as special effects in movies and in theatre, and as the price has driven down more and more filmmakers have been able to afford their usage in their own films.
Special effects that can be created with a fog machine are very plentiful and can grow with your imagination. Of course the most obvious application is to create fog itself. However, it can also be used to mimic smoke from a fire, to create steam effects, or even just to provide a general ambience or creepy mood to a scene.
The usages of fog machines in special effects are plentiful, and they are sure to keep growing as fog machines become more and more accessible.
Halloween
A fog machine is often used to add a touch of creepiness to any situation. As such, Halloween is the perfect occasion to whip out a fog machine and decorate the place with an eerie or mystifying display. Due to their reduction in price and higher widespread availability beginning primarily between 2003 and 2005, fog machines are now commonly used for household Halloween presentations. No matter the size of your Halloween display, a fog machine could work.
Whether you need it to create a scary atmosphere around your house, or run a commercial application such as a haunted house or a Halloween store, you could find a fog machine very helpful. They are even used in the creation of many horror movies.
Photography
Similar to their usage in film, many photographers have found new and creative usages for fog machines.
In most cases, fog machines are used to add a special ambience to a photo. They are also useful to make the subjects really stand out. By covering the background in a subtle fog, it can eliminate distractions so that the eyes are drawn to the subject.
Fog machines can also be used to mimic effects, similar to how they are used in film. They can create effects for smoke, fog, or other creative ideas. A crafty photographer will surely find many usages for a fog machine.
Sports Venues
Fog machines are finding increasing applications in sports venues of all kinds. Because they are so accessible these days, you might see them in anything from a high school competition to a professional sports venue.
Fog machines can create an epic scene as the team enters the field, or even to accompany the celebration when the home-team scores. Even in a professional sports context, you might see a fog machine used in everything from a pre-game introduction, to a half time show, to in-between breaks in play. Fog machines are heavily employed in the world of sports.
Weddings
Fog machines are seeing increasing use in weddings. Similar to their usage in nightclubs, haze can really amplify lights and give your wedding a party atmosphere (if that is your goal).
A ground fog machine can also create low-lying fog to be used on the dance floor to give that “dancing on clouds” feel to the guests. Because fog machines are so portable and accessible these days, we expect to see their usage in weddings continue to increase.
Industrial Uses
Fog machines have also become prevalent in various industrial applications other than the entertainment industry. That is because fog machines are easy to use, rugged and portable. A few favorite applications of fog machines include environmental testing (like HVAC inspections) and disaster response and emergency personnel training exercises.
Fog machines are especially helpful in HVAC inspections for testing leaks. By shooting fog into the ducts, the leaks are easy to spot based on where the fog exits. Many HVAC inspectors have portable fog machines which are used especially for this purpose. In fact, fog machines can be used to test leaks across a variety of other applications as well.
Cleaning companies use ultra-low volume fog machines for pest control. They have a small droplet size, which is optimum for pest control. Cold fogging, in particular, is sufficiently dense and can penetrate inaccessible areas.
Several organizations in Canada and Europe have developed a rapid deployment fog machine. These machines are used as hold-up and intrusion security systems and can disorient an intruder easily by filling a space with fog if an alarm is triggered using the panic button on a security device.
These fog machines can generate up to a thousand cubic meters of fog in just 30 seconds in a broad range of industries, including buildings that need a higher level of security, like jewelry shops and banks, but also offices, warehouses, and retail premises.
Is It Dangerous to Inhale Clouds of Fog From A Fog Machine?
Fog machines do include certain hazards and health issues that you should watch out for if you plan to use a fog machine in any way.
Atmospheric effects created with dry ice and water or liquid nitrogen may lead to asphyxiation or breathing problems. As both nitrogen and carbon dioxide can displace atmospheric air including the oxygen, they pose a risk of anoxia (commonly known as lack of oxygenation) for individuals in these atmospheres.
As a result, proper ventilation is necessary to make sure healthy, breathable air surrounds technicians and artists. Besides, carbon dioxide used in fog machines has the additional risk of meddling with a person's normal breathing reflex that is quite sensitive to the level of carbon dioxide present in the air.
Although nitrogen does not have any adverse effect on your breathing reflex, it poses its own risk in that people inhaling pure nitrogen could easily lose consciousness due to the lack of oxygen in the air without showing any warning signs. On the other hand, fog created with pure liquid air does not carry the same risk as liquid nitrogen or carbon dioxide. That is because moist air has a similar composition as standard atmospheric air.
A majority of fog machines that produce their effects using only water, like pressurized or ultrasonic technology, often do not pose any health risks. However, always keep in mind that "water-based" smoke or fog fluid contains glycol. Exposure to glycol smoke or fog can cause nausea and dizziness, headaches, tiredness and drowsiness in the short term.
On the other hand, long-term exposure to glycol smoke or fog can lead to voice and upper airway symptoms. Finally, extended exposure, lasting over several years, to fog and smoke can cause both long-term and short-term respiratory health issues.
As you can see, there are many considerations that you should know about before heavy use of a fog machine. You should make the effort required to lower exposure, especially to theatrical fog or smoke.
What is Fog Juice?
Fog machines generate a dense and thick vapor that is similar to smoke or fog. They vaporize a solution called fog juice and pump this gas into the open air. As soon as the mist comes in contact with moisture present in the air, the vapor condenses and forms a thick fog.
Fog juice is quite a versatile solution, and can be made to produce many different types of effects depending on what it is made out of, and which fog machine it is used in. It is thus very important to examine the ingredients carefully, and also be sure that the fog juice you are using works well with your fog machine. This way, you can be sure that you achieve the desired fog effect that you are searching for.
It is dangerous to mix fog juice at home; however, you could safely produce specific types of fog juices that use water and glycerin.
DIY Fog Juice
You can make your own fog machine juice at home, but you should ensure first that you are experienced in handling these types of chemicals.
You should always use distilled water for making all types of fog juices at home as ordinary water can clog your fog machine with its mineral deposits. Buy glycerin, which you can safely mix at home. Fog machine fluids made using glycerin will produce haze or light fog, rather than the dense, rolling fog used by nightclubs.
Choose a suitable mix of glycerin and distilled water for the desired effect. A five percent mixture of glycerin will generate a light haze, while a ten percent mixture will create a medium fog and so on.
Dispense a suitable amount of glycerin in a plastic container and then add the required quantity of distilled water. Then close or seal the container and vigorously shake it to ensure the ingredients mix.
Will A Fog Machine Set Off A Fire Alarm?
The answer to this depends on the type of smoke detector. It is likely that small water-based particles in high concentration may set off some kinds of smoke detectors. This problem is mostly encountered with optical sensors, as they treat these water particles like smoke.
The best idea is to check your smoke detector beforehand to ensure that you can properly use a fog machine without disturbances or safety hazards.
Maintenance Tips
Regular maintenance and fog machine cleaning is essential for its longevity. Follow these tips to clean and maintain your fog machine.
Conclusion
We have discussed what a fog machine is and how it works. We have looked at the different types of fog machines such as heated fog machines and haze machines. We then discussed the different types of fog that can be created. We have also looked at the various uses of fog machines such as in theaters, nightclubs, concerts and industrial applications.
We have also discussed why inhaling fog clouds can be detrimental to your health. We have explained what fog juice is and how you can prepare it at home. We have highlighted why some types of fog machines can trigger smoke or fire alarms.
Finally, we have provided some useful tips to maintain your fog machine. Our buying guide will discuss the different features that you should consider when buying a fog machine along with some recommendations.
We hope you have found this guide very helpful, whether you are looking to purchase a fog machine yourself, or whether you were just interested in learning more about this interesting topic. As you have seen, the usages of fog machines are vast and expanding.
The increased portability and accessibility of these machines also means that you can use them yourself for a variety of applications. You can even use your own creativity to think of uses that are wholly unique. Thank you for reading, and have fun fogging.
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