Air-water guns continue to make efficiency gains, achieve greater ease of use, and become automation-ready. Low-e guns, once defined by the use of less than 100 cfm of air, now consume as little as 20 cfm—with little loss of productivity. Multi-stage machines provide the means to keep production near the maximum curve. A lot has been happening in the air/water arena.

Ease of use has been a major push. It ranges from more accessible valve controls to lighter weight equipment and, of course, automated operation (we’ll have more to say about that in a separate article next issue). For many installations, fixed-flow guns can be both efficient and simple to operate. For areas that conduct the greater portion of their snowmaking in marginal temperatures, fixed-flow equipment can be a good option.

Multi-stage guns seek efficiency by keeping output close to the temperature production curve. Most suppliers agree that, for manually-operated multi-stage guns, four stages of flow is about the maximum snowmakers can handle. But some automated systems offer continuous adjustment, to match the curve.

Future-proofing is another trend. More than one supplier is moving to modular valve controls, so that a system can be installed with manual controls, and upgraded in steps toward full automation. Some guns themselves are becoming modular—areas can change heads to upgrade to new technology.

In all this, the overarching focus is on energy consumption. “Low-e” was the catchphrase that caught resorts’ attention years ago, and energy has become an even bigger concern since.

Just what constitutes “low-e”? An air/water ratio of 1:1 or less is one criterion, according to some suppliers; others suggest air volume under 100 cfm.

“Low-e is hard to pin down,” says HKD president Charles Santry. “Efficiency varies with temperature, so it starts with comparison to other gun types.” For example, a low-e tower might use a 1:2 air/water ratio at 20 degrees. It doesn’t take much energy to convert water to snow. But at 28 wet bulb, the snowgun has to do a lot of the work, and might run a 5:1 or 6:1 ratio. That’s still low compared to a traditional internal-mix gun with a ratio of 20:1 or 30:1.

The low-e gun “is designed very specifically to maximize snow production with a minimum of compressed air,” Santry concludes. That may be as specific as it gets.

Here’s a look at the current range of air/water guns, low-e and otherwise.


HKD
HKD has adopted a modular design, so that any product—from the fixed-flow models to the multi-stage SV10 Impulse—can be installed on a common delivery system. Changes only require replacing the head and/or the base. “This gives winter resorts flexibility for the future,” says Santry.

HKD’s models are mostly differentiated by their nozzle configurations. The Focus and Genesis are fixed-flow external-mix machines. The Ranger is an internal-mix with the SV nozzle shape. “Some areas’ systems work better with an internal-mix gun,” says Santry, and, if the water supply is on the warm side, the Ranger can use slightly less air.
Multi-stage models offer different spray patterns. The two-valve, four-stage Impulse uses both internal and external nucleation, and can decrease air flow as water flow increases. At lowest temperatures, the Impulse can go well below a 1:1 air/water ratio. At higher temperatures, though, with the added air, the Impulse can flow more water.

A year ago, HKD developed the SV10 Impact for terrain parks. “Cutter’s Camp was eye-opening for us,” says Santry. “You see the amount of energy that goes into parks.” For such situations, the new SV 15 Method, based on the Impact, is designed to produce higher flow and a fuller plume.


JOHNSON CONTROLS
Johnson Controls’ guns are designed with the system in mind. “We always have the concept that everything will be integrated,” says engineer Jean Petit. “So we design our guns a little differently. We think in terms of how we will control the guns automatically.” But the guns can be set up for manual operation, too, and are automation-ready for the future.

The low-e guns are designed to operate across a wide temperature range, often at marginal temperatures. The two tower models are the Rubis EVO and Safyr. The four-stage Rubis EVO is an external mix gun. The new model has improved performance in terms of temperature and pressure startup operation.

Safyr varies the size of the snow particle with temperature: the colder, the bigger. It can provide a continuously-variable flow rate, thanks to automation, and that allows it to flow from 10-12 gpm up to 200 gpm at coldest temperatures.

The Borax remains one of the most efficient internal-mix a/w guns, says Petit, ranging from a 20:1 air/water ratio at startup down to less than 1:1 at very cold temperatures. When automated, it, too, can be adjusted continuously.


LARCHMONT
There have been few major changes to this line, aside from hard-coating of the nozzles. That helps the nozzles retain their shape, and thus remain more productive longer. Hard-coated nozzles last “five times longer,” says company president Joe Tropeano. “Hard-coating is more cost-effective than ceramic nozzles. We’re working on some stainless steel nozzles for towers, to make them last longer, because the nozzles are more critical.” Other changes: the Z-1 gun has been operating 24 percent more efficiently, Tropeano says, and Larchmont has added a 10-foot Z1 tower option that “has been producing 38 percent more snow” compared to the regular ground gun, thanks to the added hang time, he adds.


RATNIK
Ratnik has been retrofitting its bigger Snow Giant II + II and V machines to use a lot less compressed air, while converting the same amount of water. Ratnik has rebuilt about 10,000 guns since it started updating them three or four years ago.

The new three-stage Sky Giant VI tower, developed over the past three years, was tested at 15-20 areas last winter. “We got good feedback and incorporated a few suggestions from the areas,” says president Ron Ratnik. “It has nice throw; the nozzles are arranged in such a manner that the plume is consistent.”

The secret is in the nozzles, Ratnik says. “We make our own nozzles, so they operate exactly as we think they should. We can create a concentrated plume that gets more distance. And we can get the right capacities to saturate the plume, and create the right size particles.”

He adds, “It can start up at about 30ºF. If we run at 28º, we have the same or better flow as a fan gun. And the guns are less expensive.”


SMI
SMI offers both the Viking V2 low-e tower and the single-flow Viking Kid. The four-stage V2 can be operated both manually and automatically via the SmartSnow system.
SMI has worked on the head to make it more reliable in all wind conditions, i.e., less prone to icing and freeze-up. “You do that with nozzle positioning, material types and thicknesses in the head,” company president Joe VanderKelen notes. “We’re constantly looking at nozzle and nucleator configurations.” In other recent refinements, he adds, “We’ve made towers more portable, easier to dismantle and maintain.” Tool-less construction makes them simpler to work on.

The Vikings can be configured as resorts want, from as little as 10 cfm of air up to 150 cfm—though new installations often use less than 50 cfm, he says.


SNOWNET GROUP
Snownet Group offers two low-e tower product groups, Gemini Power and the new Gemini Eco series. These Austrian-built guns use just 20 to 25 cfm of air, depending on the nozzle configuration. In the Power duo, the Power is two-stage, Power + is four-stage, with seven steps (and for automated systems only). Both have two nucleators. The Power can run on hill air or on an onboard 5 hp compressor. The new Eco group consists of the fixed-flow Eco and the three-stage Eco +. Both are designed for extremely marginal startup temperatures, a common requirement at ski resorts. A new nozzle head on the Eco + is said to guarantee no freezing. All models are available with compressor or hill air, and all can be automated and integrated with Areco fan guns and the V7 software.


TECHNOALPIN
Celebrating its 20th anniversary, Techno­Alpin has added a new tower gun, the V3, with a new three-nucleator head. It complements the existing V2, A9 and A30 models. The V3 design “maximizes heat transfer from water to the head, so that the surface won’t freeze,” says CEO Geir Vik. The V3 uses less air than the A9—25 cfm vs. 44 cfm—while flowing the same amount of water. Startup temperature is 29 wet bulb.

For ease of use, the control valves have been relocated from the vault to the base of the unit, eliminating flooding issues, and they have become modular. So resorts can start with a simple manual system, then upgrade in steps all the way to full automatic. A fully automatic gun has a pressure control valve that allows the system to smooth out and maximize the production curve at all temperatures, Vik notes. The V3 can also be set up with an onboard oil-free compressor for use without hill air.

The V series uses ceramic nozzles in an anodized aluminum housing for durability; these keep the spray angle consistent. For use in very cold temperatures, resorts can add a heater to pre-heat the water. And V series guns have a water filter that’s easy to access and clean.

The 12-foot sled tower version of the A30 is also new; specs are identical to the regular A30, though startup temperature is lower, at 24 wet bulb, due to its height.


TOPGUN
TopGun now offers three low-e towers, the fixed-flow TopGun, the nine-stage Pipe Dream, and new Two Stage. As with the company’s other guns, the new model delivers the goods in a light, low-cost, low-energy design.

The new gun uses the same basic technology as the nine-stage, says founder Troy Jervas, but is simpler to operate: as temperatures drop, just add water. It uses the same valving as the nine-stage, and shares many of its parts. The two stages are controlled from the base of the gun. Water flow rate can range between 15 and 80 gpm, and it uses 45 to 100 scfm of air.

Jervas says the nine-stage Pipe Dream provides better throw than most stick guns, as its four nucleation nozzles and nine water nozzles make it “almost like a mini fan gun, with a much more linear or cylindrical throw.”

The light weight of all the TopGun models (see chart on-line for details) is achieved by using a 1 1/2-inch tube for the tower, with just one tube each for water and air, and with all valving in the head.


TURBOCRISTAL
There’s a new multi-stage Cristalizer to complement the fixed-flow LP towers. The new gun shares some of the same characteristics of the LP: it’s relatively light, easy to move, and available on a sled or towers up to 30 feet.

The Cristalizer is a four-stage design in which the air flow can be cut in the later stages, from 100 cfm at startup to as low as 25 cfm. “So it’s possible to start at high temperatures with high output,” says sales manager Ismael Fréchette, “and you can reduce pressure and cost at low temperatures.” It uses both internal and external mix nucleation. The head is a single block, with good throw, he adds.

The LP comes in a variety of nozzle configurations, to match the gun to trail width and volume needs. Its aim is maximum production in marginal temperatures—when most areas are keenest to make snow. As with the Cristalizer, snowmakers can reduce air pressure as temperatures drop, to as little as 35 psi at about 20 degrees F.

Another new feature: the towers have a new standard jack that can be adjusted from the back. “This idea came from Camelback,” Fréchette says. “The water is connected from the back; so it makes sense. Also, this makes it easier to work on a padded tower.”

IDE—A DIFFERENT TAKE
The IDE All Weather Snowmaker is such a new and dramatic change from mainstream snowmaking that it’s hard to comprehend how it compares. But we’ll try.

The greatest benefit to the IDE system is its ability to make snow at any ambient temperature. That’s because the process uses vacuum technology. While traditional systems use volumes of compressed air, IDE’s process uses energy to remove it. In the 40-foot-tall, 16-foot diameter IDE Vacuum Ice Maker, water is exposed to a deep vacuum. The drop in temperature causes much of the water to freeze, creating a water-snow mixture and forcing a small portion of the water to evaporate. The water vapor is constantly being removed to maintain the vacuum, and the snow mix is fed into a “snow concentrator” that extracts the water, leaving a spring-like corn snow (grains are .02- to .04-inch diameter). The snow is removed from the top of the system, which is as tall and nearly as stout as the VIM itself, and sent down a slide, to be distributed on­slope by grooming machines. IDE offers two different capacities, the bigger of which produces about 1.5 acre/feet of snow a day.

Installation costs run $3 million to $4 million, depending on the size of the unit. As some North American areas have run the numbers, weighing the cost of a system against, say, the lost revenue of a snowless December holiday season, they are beginning to conclude that the system can provide a reasonable form of no-snow insurance. Would areas benefit from extending the season as well? That, too, figures into the equation.

As resorts consider the implications of IDE’s equipment, they are finding more potential uses for it. For example, the effort and cost that were required at Cypress Mountain to host the Olympic snowboarding events has led the Sochi Olympic organizing crew to investigate the possibility of installing IDE systems at several venues for the 2014 Games, from cross-country to Alpine venues.

Once installed, the energy cost to operate the system is perhaps 15 percent more than a traditional air/water or fan system, says Rafi Stoffman, the now former sales and marketing director for IDE in North America (Sam Kramer is the new North American marketing and sales director.) And it’s an environmentally friendly system.