In the 1950’s, the United States was hit with an unusually cold and dry winter. The ski season was highly affected and many ski resorts were only open for a few weeks. The problem was that there wasn’t enough snow to ski on. To solve this, Canadian jet engine researchers found that water kicked up from the jetwash of the engines often froze into snow. Ideas were hatched and eventually the first snowmaker was formed by Wayne Pierce in Milford Connecticut. 

Today, the world uses snowmaking machines more than ever. Advancements in snowmaking technology and the increasingly challenging winters have caused more snowmaking equipment to be used around the globe. Resorts are able to make snow earlier and later in the ski season, with some resorts being completely dependent on snowmaking technologies. As time goes on, I can only imagine snowmaking equipment will become increasingly necessary. In this blog, I will break down the ways in which snowmakers work to provide the world with snow to ski on.

To begin, snowmaking requires certain conditions: dry air and cold air. As we all should know, water freezes at 32 degrees Fahrenheit, but just because the air is freezing doesn’t mean we can make snow. The air also has to be dry. Snowmaking works on the principle of evaporative cooling. As water evaporates into the atmosphere, it cools whatever the water is in contact with. In the case of snowmaking, water evaporating from a water droplet causes the remaining water in the droplet to cool down. This is why the air needs to be dry. Humid air is less likely to absorb moisture, which means that the effect of evaporative cooling won’t be as strong. Dry air will absorb larger amounts of water, making the process of freezing the droplets work much better. 

Now onto the snowmaker itself. There are two types of snowmaking machines: fan-guns and compressed air guns. I will cover both types as they are both widely used and have their individual benefits. Compressed air guns are the original type of snowmaking machine. They work entirely on the principles of adiabatic cooling and evaporative cooling. As mentioned in the blog about refrigerators, adiabatic cooling occurs when a fluid goes from a highly compressed state to a low pressure state. In the context of a snow machine, compressed air is fed into a nozzle which sits on top of a tower. A much smaller amount of water is then fed into the nozzle as well. This mix of air and water creates an incredibly high pressure mist of water and air. The rapid pressure loss upon exiting the nozzle freezes the water, letting it fall as snow. Any water that is not yet frozen freezes as it falls to the ground. 

The next type of snowmaker is a fan-gun. Fan-guns are much quieter, energy efficient, and can make much more snow. They also work on the principles of adiabatic cooling and evaporative cooling, but they also work to allow the snow as much time in the air to freeze as possible. Fan guns start with the nucleator nozzle. This nozzle is essentially the same as a compressed air snowmaker, but it creates a much finer mist. The nucleator nozzle sits in the heart of the fan-gun, in front of a large fan. The fan is rimmed with many, much larger, water-only nozzles. When a fan-gun is running, the nucleator nozzle sprays microscopic, super-frozen, pellets into the much coarser water stream. The super-frozen pellets fly through the spray from the other nozzles, freezing them as well. Then the fan that sits behind this apparatus blows the snow as far as possible, to give it ample time to freeze. 

At this point, the snow is being made! Overnight, the groomers will smooth out the piles, and skiers can ride on the snow the next day. While the fake snow isn’t the same as fresh Colorado powder, it still provides a fun surface to ski on. When you think about it, ski resorts are literally creating their own snow storms!