Snow cannon

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Full blast snow cannon at The Nordic Centre, Canmore, Alberta, Canada

A snow cannon (also called snowgun, snow maker or snow fan) is a device used to produce snow artificially. The term artificial snow is mistakenly used for the produced snow; a more accurate term is man-made snow. A snow cannon works by atomizing water and allowing it to freeze into snow. The device is often used by ski hills and ski resorts to supplement naturally occurring snow and extend the skiing season. However, for the purposes of skiing, most enthusiasts consider man-made snow to be inferior to naturally occurring snow. This is due to the fact that man-made snow does not form snow flakes like natural snow; instead, man made snow forms crystals that are more dense than natural snowflakes.

Snow cannon constructors have been following these aims:

to maximize the amount of snow made,
to extend the period in which snow can be made,
to minimize the amount of energy needed,
to minimize the impact on the environment.

With global warming the ability of snow cannons to function in high temperatures has become very important, but it should be noted that their high usage of both water and power are also increasing this effect. Annually, Europe's 3100 snow cannons alone use as much energy as a city of 150,000 inhabitants and about the same amount of water as 1.5 million people in a city like Hamburg.

Homemade snow cannons are gaining in popularity.

1 Construction details
2 References
3 See Also
4 External links

[edit] Construction details

Rear view of snow cannon at Mölltaler Gletscher, Austria, showing the powerful fan.

There are two main styles of makers: a snow gun and a snow fan. A snow gun is very tall and uses higher pressure water, while a snow fan uses a powerful axial fan to propel the water jet to great distance.

A modern snow fan usually consists of one or more rings of nozzles which turn high pressurized water into small droplets. A further ring of nozzles is fed with a mix of water and compressed air and produces tiny crystals of ice. The small droplets of water and the tiny ice crystals are then mixed and propelled out by a powerful fan, after which they further cool through evaporation in the surrounding air when they fall to the ground. The crystals of ice act as seeds to make the water droplets freeze at 0°C (32 °F). Without these crystals water would supercool instead of freezing. This method can produce snow when the wet-bulb temperature of the air is as high as -2 °C (28.4 °F). The lower the air temperature is, the more and the better snow a cannon can make. This is the main reason snow cannons are usually operated in the night. The mix of all water and air streams and their relative pressures is crucial to the amount of snow made and its quality.

If conditions are below the curve snow can be made.

Wet-bulb temperature is considerably lower than dry-bulb temperature when air relative humidity is low. Wet-bulb temperature takes into account that the water droplets cool themselves by evaporation. Artificial snow can be made when the (dry-bulb) air temperature is as high as 4.5 °C (40 °F).

Modern snow cannons are fully computerized and can operate autonomously or be remotely controlled from a central location. Operational parameters are: starting and stopping time, quality of snow, max. wet-bulb temperature in which to operate, max. windspeed, horizontal and vertical orientation, sweeping angle to cover a wider area, sweeping may follow wind direction.

The snow cannon was invented by Art Hunt, Dave Richey and Wayne Pierce in 1950 ^[1] ^[2], who went on to patent it. ^[3]