Snow Making

From Fiswiki

Revision as of 22:20, 2 July 2011 by Joe (Talk | contribs)
(diff) ←Older revision | Current revision (diff) | Newer revision→ (diff)
Jump to: navigation, search
Snowmaking is the production of snow by forcing water and pressurized air through a "snow gun" or "snow cannon", on ski slopes. Snowmaking is mainly used at ski resorts to supplement natural snow.
Snowmaking is the production of snow by forcing water and pressurized air through a "snow gun" or "snow cannon", on ski slopes. Snowmaking is mainly used at ski resorts to supplement natural snow.

Snowmaking is the production of snow by forcing water and pressurized air through a "snow gun" or "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. Indoor ski slopes often use snowmaking. They are generally able to do so all 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. Feedler is the known creator of this "snow-gun".

Basically, snow is small particles of ice. So, the really old way of making snow, and the way they still do in the tropics and for special events, is to grind up blocks of ice. However, this is very expensive and labor intensive for larger scale requirements, so, if possible, machines that convert water into snow directly and on site are used.

These snowmaking machines make snow by breaking water into small particles, cooling the water by causing them to move through cold air, nucleating the water particles and distributing the resulting snow on a surface.

Why don't people just sprinkle water to make snow? Water is a unique material, it expands when it freezes and it has high heat of fusion, thus your ice cubes float and last a long time.

Heat of fusion means that one can cool a pound of water say from 65°F (18.3°C) to 64°F (17.8°C) or 34°F (1.1°C) to 33°F (.6°C) by removing 1 BTU.

But to convert one pound of liquid water at 32°F (0°C) from a liquid to one pound of ice at 32°F (0°C) requires the removal of 144 BTUs.

In summary, a large amount of heat removal (cooling) is required in snowmaking. Also, water can be cooled well below 32°F (0°C) and still stay a liquid unless it is nucleated. This phenomenon is called supercooling.

So a snowmaking machine:

  • (a) breaks the water into small particles
  • (b) cools the water to 32°F (0°C)
  • (c) removes the heat of fusion
  • (d) nucleates. Snowmaking requires relatively large quantities of water, for example, to cover an area of 200 feet (61 meters) by 200 feet (61 meters) with 6 inches (15 centimeters) of snow, one would need 20,000 cubic feet (566 cubic meters) of snow or 1,000 cubic feet (283 cubic meters) of water. This is 82,000 gallons (310,000 liters) of water or 11 truck tankers full. Thus, an excellent water supply is needed and the water pressure should be at least 100 PSI (pounds per square inch) (7 Bar) or 230 feet TDH (total dynamic head).

Many ski areas can convert over 5,000 gallons (18,900 liters) per minute of water into snow. This is 20 tons per minute or 1,250 tons per hour. Or stated another way, a truckload every minute.

Snowmaking, while usually used at ski areas, is also used for frost protection on construction projects, freeze protection of crops, automotive and aircraft testing, and sewage disposal.

[edit] Also see

[edit] External Reference

  • Backyard Blizzard: see [2]
  • Snow at Home: see [3]


[edit] Reference

  • Wikipedia Snowmaking [4]
  • Made How [5]
  • SMI Snowmaking 101 [6]

Return to Snow and Weather Glossary, Working with Snow, Freestyle Skiing

Personal tools