Fog machine

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

A fog machine (also called a smoke machine) is a device which emits a dense vapor that appears similar to fog or smoke. This artificial fog or smoke is known as theatrical smoke and fog within the entertainment industry. Most fog machines create the fog by either vaporizing a water and glycol-based or glycerine-based fluid or by atomizing mineral oil. For glycol-based fogs, the fluid (fog juice) is injected into a heated block, and evaporates quickly. The resulting pressure forces the vapor out of the exit. Upon coming into contact with cool outside air the vapor forms a fog.

1 Adverse Effects on Respiratory Health
2 Maintenance
3 See also
4 References
5 External links

[edit] Adverse Effects on Respiratory Health

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

Although often believed to be safe to breathe, theatrical fogs can cause adverse short and long-term respiratory effects in exposed performers and crew members, especially those with respiratory problems (such as asthma). One should therefore avoid breathing generated smoke or fog.^[1] Although more expensive and often less convenient, it is safer to add smoke effects digitally in postproduction of films than to use theatrical smokes on set. Glycol-based fog is associated with headaches, dizziness, drowsiness and tiredness in those exposed. These results would be expected given that glycols share some chemical similarities to alcohols and given the small size of fog particles making it easy for them to enter the bloodstream.

Fog machines are used to create spooky effects 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^{[citation needed]}, fog machines have become widely used for domestic halloween decorations.

Fog machines are also useful for industrial purposes, such as visualising the flow of air, such as over a surface in a wind tunnel or testing filters in air conditioning. Fire fighters also use fog machines in their training.

Because of the reflective and refractive qualities of the smoke created by fog machines, they are often used in nightclubs to enhance the effects of lighting and laser arrangements (see also light beam).

Haze machines, (also called haze generators), are taking over the job of fog generators for highlighting lighting or laser effects. Haze machines are often seen with bands and bigger venues when a lighting effect may need to be visible in the air.

[edit] Maintenance

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Visual Effect produced using a fog machine, conventional lighting, and an ion laser.

Fog, smoke and haze machines that operate on a fluid (rather than dry ice) must be cleaned periodically to prevent buildup within the thin tubing. This is best accomplished by draining any remaining fog juice, replacing it with a solution of 20% white vinegar and 80% distilled water, then operating the machine until it emits nearly invisible steam.

[edit] See also

Dry ice, also used for creating theatrical “smoke”.

[edit] References

^ Sunil Varughese, Kay Teschke, Michael Brauer, Yat Chow, Chris van Netten, and Susan M. Kennedy (2005). "Effects of theatrical smokes and fogs on respiratory health in the entertainment industry". American Journal of Industrial Medicine 47 (5): 411-418. DOI:10.1002/ajim.20151.