Snow cannon

Snowmaking is the production of snow by forcing water and pressurized air through a "snow gun," also known as a "snow cannon", on ski slopes. Snowmaking is mainly used at ski resorts to supplement natural snow. This allows ski resorts to improve the reliability of their snow cover and to extend their ski seasons from late autumn to early spring. Indoor ski slopes often use snowmaking. They can generally do so year-round as they have a climate-controlled environment.

The production of snow requires low temperatures. The threshold temperature for snowmaking increases as humidity decreases. Wet bulb temperature is used as a metric since it takes air temperature and relative humidity into account. Snowmaking is a relatively expensive process in its energy use, thereby limiting its use.

Art Hunt, Dave Richey, and Wayne Pierce invented the snow cannon in 1950, but secured a patent sometime later. In 1952, Grossinger's Catskill Resort Hotel became the first in the world to use artificial snow. Snowmaking began to be used extensively in the early 1970s. Many ski resorts depend heavily upon snowmaking.

Snowmaking has achieved greater efficiency with increasing complexity. Traditionally, snowmaking quality depended upon the skill of the equipment operator. Computer control supplements that skill with greater precision, such that a snow gun operates only when snowmaking is optimal. All-weather snowmakers have been developed by IDE.

The key considerations in snow production are increasing water and energy efficiency and increasing the environmental window in which snow can be made.

Snowmaking plants require water pumps and sometimes air compressors when using lances, that are both very large and expensive. The energy required to make artificial snow is about 0.6 - 0.7 kW h/m³ for lances and 1 - 2 kW h/m³ for fan guns. The density of artificial snow is between 400 and 500 kg/m³ and the water consumption for producing snow is roughly equal to that number.

Snowmaking begins with a water supply such as a river or reservoir. Water is pushed up a pipeline on the mountain using very large electric pumps in a pump house. This water is distributed through an intricate series of valves and pipes to any trails that require snowmaking. Many resorts also add a nucleating agent to ensure that as much water as possible freezes and turns into snow. These products are organic or inorganic materials that facilitate the water molecules to form the proper shape to freeze into ice crystals. The products are non-toxic and biodegradable.

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Wikipedia