Fog machine

Last updated

A fog machine, fog generator, or smoke machine is a device that emits a dense vapor that appears similar to fog or smoke. This artificial fog is most commonly used in professional entertainment applications, but smaller, more affordable fog machines are becoming common for personal use. Fog machines can also be found in use in a variety of industrial, training, and some military applications. Typically, fog is created by vaporizing proprietary water and glycol-based or glycerin-based fluids or through the atomization of mineral oil. This fluid (often referred to colloquially as fog juice) vaporizes or atomizes inside the fog machine. Upon exiting the fog machine and mixing with cooler outside air, the vapor condenses, resulting in a thick, visible fog.

Contents

A small fog machine for residential use. Neblmaschine.jpg
A small fog machine for residential use.

Types

Heated

Interior view of a fog machine, showing the pump and heat exchanger. Fogger Insides.JPG
Interior view of a fog machine, showing the pump and heat exchanger.

Heated fog machines use either an inert gas or an electric pump to propel mineral oil, propylene glycol, or glycerin and water mixture into a heat exchanger, where the solution is vaporized. The most commonly encountered form of heated fog machine is the pump machine. Very basic models of this type of machine consist of a fluid reservoir, an electric pump to move the fog fluid, and a heat exchanger, which vaporizes the fluid. More complex models may include a variety of other features, including variable speed pumps to control the output of fog, timer modules, or components for remote operation and monitoring of the fog machines' status. Some manufacturers have produced accessories and fluids that when combined with an ordinary heated pump machine, create fog effects similar to chilled fog machines. Gas propelled fog machines use an inert gas (most commonly CO2 or nitrogen) to propel either mineral oil or a glycol based fluid into a heat exchanger, where it is vaporized into particles, creating a fog. Some models of gas propelled fog machine provide control over the output of fog by varying the volume of gas used to propel the fluid.

Chilled

Chilled fog machines are designed to create thick clouds of fog that lie close to the ground and dissipate as they rise. They are typically created by using either dry ice, compressed liquid CO2, liquid nitrogen, ice or more recently liquid air.

Generic Dry Ice machine made from a 3G. drum. DryIceMachine.JPG
Generic Dry Ice machine made from a 3G. drum.
Sublimation of dry ice DryIceSublimation.JPG
Sublimation of dry ice

Dry ice (solid CO2) effects are produced by heating water to or near boiling in a suitable container (for example: a 55-gallon drum with water heater coils in it), and then dropping in one or more pieces of dry ice. Because at standard temperature and pressure carbon dioxide is a gas, the carbon dioxide sublimes and instantly produces a gas, condensing water vapor and creating a thick white fog. Liquid nitrogen (N2) can be used in a similar manner to dry ice. In either case, a fan placed at the top of the container directs the fog where it is needed.

Liquid air is an alternative to using liquid nitrogen in generating low lying fog effects. Liquid air is composed of N2 and O2 mixed in a ratio of 79% nitrogen and 21% oxygen stored as a liquid in insulated cylinders. This ratio of nitrogen to oxygen is the same as that of atmospheric air, and indeed liquid air may be fabricated by simply liquefying atmospheric air. Liquid air can be used as a direct replacement for liquid nitrogen in chilled-fog effects and is intended to be used in the same manner in the same equipment. Its key advantage over liquid nitrogen is that it presents no asphyxiation hazard, since it contains oxygen. A disadvantage is that it supports combustion, whereas liquid nitrogen inhibits combustion.

Uses

A heavy duty smoke machine feeding smoke into a blower to generate fog effects for open air location filming. Smoke Machine.jpg
A heavy duty smoke machine feeding smoke into a blower to generate fog effects for open air location filming.

The versatility of fog machines make them appropriate for a wide variety of applications: Fog readily assists in creating a specific mood or feeling for a theatrical moment, and is often used in plays, such as Dracula , A Christmas Carol and Macbeth . Fog machines are also frequently used in Halloween displays such as haunted houses or forests. Because of greater availability and reductions in prices between 2003 and 2005, fog machines have become widely used for domestic Halloween presentations. Fog machines are also useful for industrial applications including visualizing the flow of air, such highlighting drag over a surface in a wind tunnel or testing for leaks or filter effectiveness in air conditioning installations. Emergency and military services also use fog machines in their training regimens. Because of the reflective and refractive qualities of the smoke created by fog machines, they are often used in nightclubs and other entertainment venues to enhance the effects of lighting and laser arrangements, although they are being superseded by haze machines (see also light beam). Several companies in Europe and Canada have developed rapid deployment fog machines for use as intrusion and hold-up security systems, intended to disorient an intruder by filling a room with fog when triggered by a panic button or other security device. These security smoke devices can produce between 300 and 1,000 cubic meters (11,000 and 35,000 cu ft) of smoke in 30 seconds and have been utilized in a wide variety of industries, including buildings requiring a high level of security, such as banks and jewelers, but also warehouses, offices, retail premises and in cash-handling chains. Concerns have been raised, that these devices may cause criminals to panic, causing them to become violent to customers or staff, [1] however security smoke now has its own European Standard EN-8 which specifically states that it must not be installed in such a way as to create a mantrap. [2]

Industrial uses

Ultra Low Volume (ULV) fogging is used by pest control industry and cleaning companies. ULV refers to the droplet size (between 20–30 micrometers (0.00079–0.00118 in)) generated by these fog machines. This fine droplet size is known [3] as the optimum size for pest control. Traditional thermal fog machine technology has difficulty reaching crawling pests such as roaches, flea, and rodents due to the droplet size being too fine (less than 10 micrometers (0.00039 in)). It is often found that small droplets are blocked by the "air-curtain" of insects and rodents.[ citation needed ] [3] Cold Fogging, in contrast, is heavy enough to penetrate these "air-curtains" as well as light enough to be evenly distributed within a room.

Adverse health effects

A special effects engineer positions the inflatable plastic tube feeding the smoke. Smoke Machine engineer.jpg
A special effects engineer positions the inflatable plastic tube feeding the smoke.

Dry ice- and liquid nitrogen-based fog

Atmospheric effects generated using water and dry ice or liquid nitrogen can present asphyxiation or breathing hazards. Both carbon dioxide and nitrogen displace ordinary air and the oxygen it contains, creating a risk of subtle anoxia (lack of oxygenation) for people working in these atmospheres. Adequate ventilation is essential to ensure that artists and technicians are surrounded by breathable air. Carbon dioxide has the added hazard of interfering with the normal breathing reflex, which is sensitive to carbon dioxide levels in the air. Nitrogen has no effect on the breathing reflex, but this creates its own hazard in that a person breathing pure nitrogen can lose consciousness from lack of oxygen without any warning signs.

Liquid air fog

Fog produced with liquid air does not present the hazards of carbon dioxide or liquid nitrogen because the liquid air has the same composition as ordinary atmospheric air (including the same level of breathable oxygen).

Fog machines which generate their effects solely using water, such as ultrasonic or pressurized technology, pose no special health risks, however "water-based" fog fluid commonly contains glycol or glycerin.

Glycerin-based fog

Glycerin has a boiling point of 290 °C (554F degrees), considerably higher than the temperature required for fog to be created. [4] Thus, the thermostable range for glycerin is unlikely to be exceeded in normal commercial fogging operation, and so glycerin will not break down into other molecules due to heat at these temperatures.

Glycerin has been tested for safety in 62 tests by the National Institutes for Occupational Safety and Health (NIOSH). These tests include toxicity testing, eye irritation, skin irritation and several others. [5]

Glycol-based fog

A number of studies have been published on the potential health effects presented by exposure to glycol-based theatrical fogs and artificial mists.

Two studies, a Health Hazard Evaluation completed in 1994 by the National Institute for Occupational Safety and Health, [6] and another one in 2000 by the Department of Community and Preventative Medicine at the Mount Sinai School of Medicine and ENVIRON; [7] both prepared for Actors Equity and the League of American Theaters and Producers, focused on the effects on actors and performers in Broadway musicals. The conclusion of both studies was that there was irritation of mucous membranes such as the eyes and the respiratory tract associated with extended peak exposure to theatrical fog. Exposure guidelines were outlined in the 2000 study that, it was determined, should prevent actors from suffering adverse impact to their health or vocal abilities.

Another study [8] focused on the use of theatrical fog in the commercial aviation industry for emergency training of staff in simulated fire conditions. This study also found eye and respiratory tract irritation.

In May 2005, a study published in the American Journal of Industrial Medicine, [9] conducted by the School of Environment and Health at the University of British Columbia, looked at adverse respiratory effects in crew members on a wide variety of entertainment venues ranging from live theaters, concerts, television and film productions to a video arcade. This study determined that cumulative exposure to mineral oil and glycol-based fogs were associated with acute and chronic adverse effects on respiratory health. This study found that short-term exposure to glycol fog was associated with coughing, dry throat, headaches, dizziness, drowsiness, and tiredness. This study also found long-term exposure to smoke and fog was associated with both short-term and long-term respiratory problems such as chest tightness and wheezing. Personnel working closest to the fog machines had reduced lung function results.

The Professional Lighting and Sound Association has compiled a standard for theatrical fogs or artificial mists compositions for use in entertainment venues that "are not likely to be harmful to otherwise healthy performers, technicians, or audience members of normal working age, which is 18 to 64 years of age, inclusive." [10] This standard was based primarily (though not exclusively) upon the findings of a report commissioned for them by the Cohen Group [11] and applies to only those fog fluid compositions that consist of a mixture of water and glycol (so-called "water based" fog fluid).

Short-term exposure to glycol fog can be associated with headaches, dizziness, drowsiness and tiredness. Long-term exposure to smoke and fog can be related to upper airway and voice symptoms. Extended (multi-year) exposure to smoke and fog has been associated with both short-term and long-term respiratory health problems. Efforts should be made to reduce exposure to theatrical smoke to as low a level as possible. The use of digital effects in post production on film and television sets can be considered a safer practise than using theatrical smoke and fog during filming, [12] although this is not always practical.

Haze machines

Haze machines, also called haze generators or hazers, produce atmospheric effects (haze) which tend to be less dense than that of fog machines, allowing them to be used in creating more subtle looks. Depending on a venue's or location's ventilation, this haze can stay in the air for hours. Because of the small particle size of the output from hazers, under 5 micrometres, a hazer typically takes longer to fill the same volume of space with a visible effect relative to a fog machine. [13]

See also

Related Research Articles

<span class="mw-page-title-main">Carbon dioxide</span> Chemical compound with formula CO₂

Carbon dioxide is a chemical compound with the chemical formula CO2. It is made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature and at normally-encountered concentrations it is odorless. As the source of carbon in the carbon cycle, atmospheric CO2 is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater.

<span class="mw-page-title-main">Nitroglycerin</span> Chemical compound

Nitroglycerin (NG), also known as trinitroglycerol (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless or pale yellow, oily, explosive liquid most commonly produced by nitrating glycerol with white fuming nitric acid under conditions appropriate to the formation of the nitric acid ester. Chemically, the substance is an organic nitrate compound rather than a nitro compound, but the traditional name is retained. Discovered in 1846 by Ascanio Sobrero, nitroglycerin has been used as an active ingredient in the manufacture of explosives, namely dynamite, and as such it is employed in the construction, demolition, and mining industries. It is combined with nitrocellulose to form double-based smokeless powder, used as a propellant in artillery and firearms since the 1880s.

<span class="mw-page-title-main">Smog</span> Smoke-like, fog-like air pollutions

Smog, or smoke fog, is a type of intense air pollution. The word "smog" was coined in the early 20th century, and is a portmanteau of the words smoke and fog to refer to smoky fog due to its opacity, and odor. The word was then intended to refer to what was sometimes known as pea soup fog, a familiar and serious problem in London from the 19th century to the mid-20th century, where it was commonly known as a London particular or London fog. This kind of visible air pollution is composed of nitrogen oxides, sulfur oxide, ozone, smoke and other particulates. Man-made smog is derived from coal combustion emissions, vehicular emissions, industrial emissions, forest and agricultural fires and photochemical reactions of these emissions.

<span class="mw-page-title-main">Dry ice</span> Solid form of carbon dioxide

Dry ice colloquially means the solid form of carbon dioxide. It is commonly used for temporary refrigeration as CO2 does not have a liquid state at normal atmospheric pressure and sublimes directly from the solid state to the gas state. It is used primarily as a cooling agent, but is also used in fog machines at theatres for dramatic effects. Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere). It is useful for preserving frozen foods (such as ice cream) where mechanical cooling is unavailable.

<span class="mw-page-title-main">Ethylene glycol</span> Organic compound ethane-1,2-diol

Ethylene glycol is an organic compound with the formula (CH2OH)2. It is mainly used for two purposes: as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odorless, colorless, flammable, viscous liquid. It has a sweet taste, but is toxic in high concentrations. This molecule has been observed in outer space.

<span class="mw-page-title-main">Propylene glycol</span> Chemical compound

Propylene glycol (IUPAC name: propane-1,2-diol) is a viscous, colorless liquid. It is almost odorless and has a faintly sweet taste. Its chemical formula is CH3CH(OH)CH2OH. As it contains two alcohol groups, it is classed as a diol. An aliphatic diol may also be called a glycol. It is miscible with a broad range of solvents, including water, acetone, and chloroform. In general, glycols are non-irritating and have very low volatility.

<span class="mw-page-title-main">Nitrogen dioxide</span> Chemical compound with formula NO₂

Nitrogen dioxide is a chemical compound with the formula NO2. One of several nitrogen oxides, nitrogen dioxide is a reddish-brown gas. It is a paramagnetic, bent molecule with C2v point group symmetry. Industrially, NO2 is an intermediate in the synthesis of nitric acid, millions of tons of which are produced each year, primarily for the production of fertilizers.

A propellant is a mass that is expelled or expanded in such a way as to create a thrust or another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the engine that expels the propellant is called a reaction engine. Although technically a propellant is the reaction mass used to create thrust, the term "propellant" is often used to describe a substance which contains both the reaction mass and the fuel that holds the energy used to accelerate the reaction mass. For example, the term "propellant" is often used in chemical rocket design to describe a combined fuel/propellant, although the propellants should not be confused with the fuel that is used by an engine to produce the energy that expels the propellant. Even though the byproducts of substances used as fuel are also often used as a reaction mass to create the thrust, such as with a chemical rocket engine, propellant and fuel are two distinct concepts.

Acrylonitrile is an organic compound with the formula CH2CHCN and the structure H2C=CH−C≡N. It is a colorless, volatile liquid. It has a pungent odor of garlic or onions. Its molecular structure consists of a vinyl group linked to a nitrile. It is an important monomer for the manufacture of useful plastics such as polyacrylonitrile. It is reactive and toxic at low doses.

<span class="mw-page-title-main">Vaporizer (inhalation device)</span> Device to vaporize substances for inhalation

A vaporizer or vaporiser, colloquially known as a vape, is a device used to vaporize substances for inhalation. Plant substances can be used, commonly cannabis, tobacco, or other herbs or blends of essential oil. However, they are most commonly filled with a combination propylene glycol, glycerin, and drugs such as nicotine or tetrahydrocannabinol as a liquid solution.

<span class="mw-page-title-main">Haze</span> Dry particulates obscuring clarity of the sky

Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of particulates causing horizontal obscuration into categories of fog, ice fog, steam fog, mist, haze, smoke, volcanic ash, dust, sand, and snow. Sources for particles that cause haze include farming, traffic, industry, windy weather, volcanic activity and wildfires. Seen from afar and depending on the direction of view with respect to the Sun, haze may appear brownish or bluish, while mist tends to be bluish grey instead. Whereas haze often is considered a phenomenon occurring in dry air, mist formation is a phenomenon in saturated, humid air. However, haze particles may act as condensation nuclei that leads to the subsequent vapor condensation and formation of mist droplets; such forms of haze are known as "wet haze".

A coolant is a substance, typically liquid, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator.

<span class="mw-page-title-main">Oxygen bar</span> Establishment that sells oxygen for on-site recreational use

An oxygen bar is an establishment, or part of one, that sells oxygen for recreational use. Individual scents may be added to enhance the experience. The flavors in an oxygen bar come from bubbling oxygen through bottles containing aromatic solutions before it reaches the nostrils: most bars use food-grade particles to produce the scent, but some bars use aroma oils.

<span class="mw-page-title-main">2-Butoxyethanol</span> Chemical compound

2-Butoxyethanol is an organic compound with the chemical formula BuOC2H4OH. This colorless liquid has a sweet, ether-like odor, as it derives from the family of glycol ethers, and is a butyl ether of ethylene glycol. As a relatively nonvolatile, inexpensive solvent, it is used in many domestic and industrial products because of its properties as a surfactant. It is a known respiratory irritant and can be acutely toxic, but animal studies did not find it to be mutagenic, and no studies suggest it is a human carcinogen. A study of 13 classroom air contaminants conducted in Portugal reported a statistically significant association with increased rates of nasal obstruction and a positive association below the level of statistical significance with a higher risk of obese asthma and increased body mass index.

<span class="mw-page-title-main">Liquefaction of gases</span>

Liquefaction of gases is physical conversion of a gas into a liquid state (condensation). The liquefaction of gases is a complicated process that uses various compressions and expansions to achieve high pressures and very low temperatures, using, for example, turboexpanders.

<span class="mw-page-title-main">Haze machine</span>

Haze machines, or haze generators, are effects machines similar to fog machines, designed to produce an unobtrusive, homogeneous clouds suspended in the air intended primarily to make light beams visible or create a subtle diffusion.

<span class="mw-page-title-main">Propylene glycol dinitrate</span> Chemical compound

Propylene glycol dinitrate (PGDN, 1,2-propylene glycol dinitrate, or 1,2-propanediol dinitrate) is an organic chemical, an ester of nitric acid and propylene glycol. It is structurally similar to nitroglycerin, except that it has one fewer nitrate group. It is a characteristically and unpleasantly smelling colorless liquid, which decomposes at 121 °C, below its boiling point. It is flammable and explosive. It is shock-sensitive and burns with a clean flame producing water vapor, carbon monoxide, and nitrogen gas.

<span class="mw-page-title-main">Theatrical smoke and fog</span> Atmospheric effects used in the entertainment industry

Theatrical smoke and fog, also known as special effect smoke, fog or haze, is a category of atmospheric effects used in the entertainment industry. The use of fogs can be found throughout motion picture and television productions, live theatre, concerts, at nightclubs and raves, amusement and theme parks and even in video arcades and similar venues. These atmospheric effects are used for creating special effects, to make lighting and lighting effects visible, and to create a specific sense of mood or atmosphere. Recently smaller, cheaper fog machines have become available to the general public, and fog effects are becoming more common in residential applications, from small house parties to Halloween and Christmas.

Inhalation is a major route of exposure that occurs when an individual breathes in polluted air which enters the respiratory tract. Identification of the pollutant uptake by the respiratory system can determine how the resulting exposure contributes to the dose. In this way, the mechanism of pollutant uptake by the respiratory system can be used to predict potential health impacts within the human population.

<span class="mw-page-title-main">Composition of electronic cigarette aerosol</span>

The chemical composition of the electronic cigarette aerosol varies across and within manufacturers. Limited data exists regarding their chemistry. However, researchers at Johns Hopkins University analyzed the vape clouds of popular brands such as Juul and Vuse, and found "nearly 2,000 chemicals, the vast majority of which are unidentified."

References

  1. ↑ "What is a fogging device?". BBC News. 8 June 2009. Retrieved 2009-07-02.
  2. ↑ Folders/prose-07-09/News-Bsiasmoke.htm BIA Welcomes new European Standard [ dead link ]
  3. 1 2 "Fog Machines: The Optimal Pest Control Droplet Size". Mackay Pest Control. Retrieved 2016-09-22.
  4. ↑ National Institute for Occupational Safety and Health [NIOSH Pocket Guide to Chemical Hazards - https://www.cdc.gov/niosh/npg/npgd0302.html Glycerin (mist) - Centers for Disease Control and Prevention]
  5. ↑ Glycerine - NIOSH Toxicity Data
  6. ↑ Burr GA, Van Gilder TJ, Trout DB, Wilcox TG, Driscoll R. NOSH Health Hazard Evaluation ETA 90-0355-2499. Actor's Equity Association.
  7. ↑ Moline JM, Golden AL, Highland JH, Walmart KR, Kao AS. Health Effects Evaluation of Theatrical Smoke, Haze and Pyrotechnics. Prepared for Actor's Equity Pension and Health Trust Funds. June 6, 2000.
  8. ↑ Weislander G, Norback D, Lindgren T. Experimental exposure to propylene glycol mist in aviation emergency training: acute ocular and respiratory effects. Occupational and Environmental Medicine. 2001 Oct;58(10):649-55.
  9. ↑ Varughese S, Teschke K, Bauer M, Chow Y, van Netten C, Kennedy SM. Effects of theatrical smokes and fogs on respiratory health in the entertainment industry. American Journal of Industrial Medicine. 2005 May;47(5):411-8.
  10. ↑ ANSI HE'.5 - 2003, Entertainment Technology - [Theatrical Fog Made With Aqueous Solutions Of Di- And Triadic Alcohols F&S/1997-3017r7.5 Theatrical Fog Made With Aqueous Solutions Of Di- And Trihydric Alcohols F&S/1997-3017r7.5]
  11. ↑ Gregory E. Raymond, Recommended Exposure Liquid Fogging Agents Archived 2013-01-19 at archive.today
  12. ↑ Teschke K, Chow Y, van Netten C, Varughese S, Kennedy SM, Bauer M. Exposures to atmospheric effects in the entertainment industry. Journal of Occupational and Environmental Hygiene. 2005 May;2(5):277-84.
  13. ↑ "Wie funktioniert eine Nebelmaschine?". www.nebelmaschine-check.de. Retrieved 13 June 2016.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.