Final answer:
The correct answer is option b. 15%, as evaporative coolers consume considerably less energy than traditional air-conditioning units due to their operational mechanism based on the evaporation process.
Step-by-step explanation:
The correct answer is option b. 15%. Evaporative coolers, also known as swamp coolers, are cooling systems that use the principle of evaporation to cool the air. They are much less expensive to operate than traditional refrigerated air-conditioning units, which require energy-intensive compressors to function. The key reason for the low operating cost of evaporative coolers is their simplicity and the use of water's phase change properties to absorb heat, resulting in cooling. While this makes them more suitable for dry environments, they are remarkably energy-efficient, operating at approximately 15% of the cost of operating a comparable refrigerated air-conditioning unit.
Evaporative coolers, also known as swamp coolers, work by evaporating water to cool the air. They do not require compressors, making them more energy efficient than refrigerated air-conditioning units. Evaporative coolers typically operate at around 20% of the cost of operating a similar capacity refrigerated air-conditioning unit.