They brought an aura of romance to W. Somerset Maugham's colonial Asia and a feeling of intrigue to Humphrey Bogart's "Casablanca" in wartime North Africa.

But for all its charm, the once ubiquitous ceiling fan seemed another victim of technological progress when air conditioning came along in the 1930s. By a decade ago, even Emerson Electric Co., which had been in the business since the late 1880s, seriously considered dropping the line for lack of sales.

As it celebrates its 100th anniversary this month, however, the ceiling fan is back in vogue. And inventor Philip Diehl, who filed the first patent application for a four-bladed, electric, belt-driven ceiling on May 4, 1881, would be amazed at how buying motivations have changed.

The owner of a large estate here, for example, bought 15 of them recently -- not for his home but for his stables. The fans were to shoo the flies off his prize horses.

An equally innovative West Coast man installed ceiling fans in his garage to keep the dust from accumulating on his Rolls-Royce.

According to ceiling-fan manufacturers, more of the appliances have been sold in the last five years here than in the preceding 95 years. U.S. ceiling-fan production 10 years ago was no more than 20,000 units a year, according to a spokesman for St. Louis-based Emerson Electric. But by last year, sales of U.S. ceiling fans topped 4 million units, the company estimates.

Part of the reason for the rapid growth was the energy crisis of 1973, which sent utility costs spiraling upward. "People became energy conscious," an Emerson spokesman says, "and that's when the business grew to its present level."

Today, most department stores carry fans, as do the large catalogue sellers, including Sears, Roebuck & Co., Montgomery Ward and J.C. Penny. Sears, which has sold various models for almost five years, says its business has doubled in each of the last two years. And others say it is among the most popular items in the catalogue.

The boom has given life to old fan producers like Emerson and spurred business for new firms such as Casablanca Fan Co. in Pasadena.

Started by President Burton A. Burton, who first saw a ceiling fan in New Orleans at Kolb's Restaurant in 1968, Casablanca became a labor love for Burton.

In 1973 he left a job in the aerospace industry to form Casablanca with five other people, and the company manufactured its first ceiling fan in 1974 -- a model admittedly patterned after one of Emerson's original designs.

The business fanned out. Within one year, Casablanca's sales hit $1.7 million, rose to $7 million in 1976 and $20 million the year after. Last year, Burton says, the company (now employing 350 people) sold more than $40 million worth of fans. With current production up to over 1,500 units per day, he expects sales for 1981 to be well over $50 million.

"The ceiling fan is here to stay," he says. "It's unique in that it was a product that went out of vogue and that has come back again. As long as energy is scarce, the ceiling fan will be in."

While ceiling fans traditionally have been used as decorative accents for homes and restaurants, there are practical reasons why the fans have gained so much attention. Not only do they reduce utility bills by up to 30 percent but they can cool down or even warm up homes, and they use no more electricty than a 60-watt light bulb, manufacturers say.

According to one industry source, setting the thermostat at 78 degrees in the summer and running the fan at the same time lowers actual room temperature to 72 degrees. Conversely, in the winter, by setting the thermostat at a low of 68 degrees and running a reversible fan which pushes the air down, the temperature can be brought up to 72 degrees as warm air that collects under the ceiling is forced downward.

Ceiling fans don't have to be expensive, either. Depending on the type of fan or the materials and accessories used, they can be bought for as little as $70 from a Montgomery Ward catalogue to as much as $2,000 for a new "Centennial" model from Casablanca crafted specially to commemorate the appliance's 100th anniversary. On the average, however, they cost around $200. Antique fans can cost as much as $13,000, as was the case at a recent auction. However, antiques are difficult to come buy and putting them into working condition is an expensive endeavor.

According to Burton, the fans can be installed in any room where the ceilings are lower than eight feet. The only recommendation he makes to a prospective buyer is that the paddles be completely parallel to the floor. In this way, optimum circulation is achieved. Burton also says wood blades are safer than metal. In fact, inserting a hand in a moving wooden fan cannot injure a person, even at higher speeds than the recommended 200 revolutions per minute.

All practical considerations aside, the ceiling fan is also an enjoyable item.

Still used in restaurants around the country, the fans mostly add atmosphere and a touch of the exotic.