I must admit, until recently I never gave much thought to how my refrigerator worked or why efficiency is so important. As long as my lettuce didn't freeze and my ice cream didn't melt I was satisfied. However, being a new homeowner and dealing with skyrocketing utility bills, my apathetic attitude has gone the way of the old ice box. Amazingly, today's home refrigerators, brimming with whiz-bang features and high-tech components, have transformed from energy hogs to misers. Even more fascinating though is how they got there.

For centuries, people used water, ice, and snow in crude attempts to refrigerate food. In the 1700s, they began to store ice for use throughout the year. Oliver Evans designed the first refrigeration machine in 1805. Based on this design, John Gorrie built a refrigerator in 1844.

Meanwhile, natural ice, placed in insulated tin or zinc-lined boxes, was commonly used to refrigerate food. In this era, others contributed to modern household refrigerators as we know them today. For example, Michael Farady, in the early 1800s, liquefied ammonia to cause cooling.

In 1889 and 1890, warm winters created natural-ice shortages that accelerated the use of mechanical refrigeration. Also in the 19th century, much effort was made to find a suitable gas to undergo compression and provide cooling. Systems were developed using compressed ammonia and sulfur dioxide as refrigerants. But by the early 20th century, after several fatal accidents, people understood that methyl chloride could be lethal if it leaked from a refrigerator. Several American companies worked together to find an alternative, less dangerous refrigerant — enter Freon in the 1930s, which became the standard for many years. Household refrigerators started appearing in the early 1900s. Two of the first debuted in Fort Wayne, Ind.: One unit unveiled by General Electric and the other, the first Guardian refrigerator, which was a predecessor of the Frigidaire. In Chicago, the Domelre debuted and by 1920, more than 200 home refrigerators were on the market. Another significant development in 1918 saw the introduction of the Kelvinator, the first refrigerator with automatic control.

Generally, refrigerators produced in this period had compressors driven by belts, which attached to motors located in a separate room. In 1926, General Electric is said to have offered the first hermetically sealed refrigerator compressor.

During the '20s and '30s, electric refrigerators with ice-cube compartments were introduced, giving consumers their first look at freezers. Home refrigerator innovation waned leading up to and through World War II. Following the war, however, mass production made home refrigerators common, and technology leapt forward as automatic defrost and icemakers debuted.

In the 1970s, environ-mental issues dramatically impacted home refrigerator design. Energy efficiency became a top concern and, eventually, new refrigerants were developed to replace ozone-depleting chlorofluorocarbons.

Better insulation, less power-hungry motors, and development of more efficient airflow give today's refrigerators their energy-saving qualities. In tandem with the efficiency evolution came attractive styles that make refrigerators as pleasing to the eye as they are to the wallet.

Think about this: At one time refrigeration, though neither easy nor reliable, used no electricity whatsoever. Then, only a few years ago home refrigerators were sending consumers' electric meters spinning. Now, energy-efficient models have cut consumers' bills in half while becoming environ-mentally friendly in the process. Chalk up another victory in the refrigerator revolution.