Henry R. Hahn is a lighting engineer and president of H & V Electric Sales & Service Inc. Projects he has worked on include the San Diego Stadium and many bridges around New York City. In 1961, he formed Infranor of North America Inc., a lighting supply company, and in December, 1967, he organized H & V to handle sales for Infranor and several other companies.
The main problem facing the operator who wants to install a lighting system is geography. Slopes must be bright enough for the skier to see changes in topography, obstacles and other skiers, under rapidly-changing conditions. The lighting fixtures must be located and installed properly so they will not create blind spots.
The three major questions to be considered are the light sources used, the fixtures and how the fixtures accomplish the overall lighting objective.
There are five major light sources in use at ski areas today—incandescent, fluorescent, mercury vapor, metal halide and ceramic discharge lamps. The differences between them are primarily efficiency, size and life.
The incandescent, either the quartz or standard type, is the least efficient but most commonly and inexpensively available. Its efficiency averages between 15 and 20 lumens of light per watt of energy. In other words, for every watt of electrical energy, the light will produce 15-20 lumens of light.
The other four lamps are similar in that they all use a gas, such as mercury, and additives of other metals in a gaseous discharge arc to create the light. With all these, some transformer ballasting equipment must be used to control the electricity flow while the arc is being formed when the lamp is lighted.
The fluorescent lamp has high efficiency, but is not generally suited to good light control over a long distance because of its large size. Also its light is poor in cold weather. Efficiency runs between 50 and 70 lumens per watt.
The mercury vapor lamp has a long life but efficiency runs between 50 and 60 lumens per watt and its size does not lend itself to effective control.
The metal halide lamp is a type of mercury lamp, with other metals added to the gases of the arc to allow a broader light spectrum and higher efficiency. It has a long life expectancy and its size lends itself to good light control.
The last lamp, the ceramic discharge, has the highest efficiency, good life and small size for good light control, but gives off a yellowish-white light and does not have quite as broad a light spectrum as the other four lamps. It is also the most expensive of the group.
After selecting a lamp type, the next step is to apply them in lighting fixtures in such a way that their efficiencies are best utilized. At one extreme we could have a bare lamp just hanging with its light going in all directions. At the other extreme, we could have a large fixture with an elaborate reflective system and even lenses so the light could be directed to a narrow spot. For top efficiency, some reflector and/or lens control must be used to direct the light in a narrow enough pattern to project it over the required distance. Figure 1 shows how good light control can increase lamp efficiency.
The light fixtures are generally set up as in Figure 2. The equipment used is generally aimed so the skier will not be looking into the lights as he skis down the hill and the equipment must have sufficient control to project the light far enough to cover the distance between fixtures.
Several sources are available to the operator for recommendations on how to light a particular slope. Architectural and engineering firms have people specially-qualified for designing lighting systems. He can also call on the lighting department of his local power company or obtain help from electrical contractors.
Of course, for successful night skiing it is also necessary to light the areas at the bottom of the slope, around the lodge and the parking lot. This is called environmental lighting and can be strictly functional, but more generally also enhances the environment and creates attractive settings.
The overall result of night-time lighting depends on the quality and attractiveness of the total scheme. It is recommended that professional help be engaged for planning, design and supervision of the installation. Since the job is unique, considerable field work will be required.
| Type | Cost, $ | Life, hr. | Efficiency Lumens/watt | Size, watts | Lumens/bulb | Rank in light quality | Rank in system cost |
|---|---|---|---|---|---|---|---|
| Incandescent | 5-10 | 1-2,000 | 15-20 | 1,500 | 22.5-30,000 | 1 | 5 |
| Fluorescent | 3 | 7,000 | 50-70 | 100 | 5-7,000 | 5 | 1 |
| Mercury vapor | 15 | 16-20,000 | 50-60 | 1,000 | 50-60,000 | 3 | 3 |
| Metal halide | 30 | 8-10,000 | 85-90 | 1,000 | 85-90,000 | 2 | 4 |
| Ceramic discharge | 35 | 10,000 | 100 | 400 | 40,000 | 4 | 2 |
