In 1981, the energy factor of a typical home refrigerator was 5.59, and by 2011 the EF increased more than three-fold to 15.50, for a 207% improvement in energy efficiency in the last 30 years (see chart). The other four home appliances tracked by the AHAM also had significant improvements in energy efficiency since 1981 based on the increases in their EF ratings. Compared to 1981, the energy efficiency of the average room air-conditioner has increased by 46%, today’s freezer is 65% more efficient, and modern washing machines and dishwashers are more than twice as energy-efficient.
As one example of how technology has improved the energy efficiency of appliances, today’s dishwashers consume less than half the energy of the 1981 dishwasher because of technological advances in soil sensors that minimize water usage, and the increased use of stainless interiors that accelerate drying time.
If the energy efficiency of the average dishwasher more than doubled since 1981, what has happened to its price, measured by the number of hours a typical American factory worker would have to toil at the average hourly wage to earn enough income to purchase a standard model? The time-cost today is only one-third of the time-cost 30 years ago, as the comparison below shows.