The kitchen is the room in the house where the most energy is consumed. Refrigerators, ovens, dishwashers and other appliances account for nearly 40% of the total energy consumed in your house. Engineers have been working for years to make them more energy efficient. To design a more efficient refrigerator, engineers at companies like Liebherr have increased the insulation thickness in the refrigerator's walls from 1/2 inch to 2 inches.
Fridge designers have also improved compressor efficiency, and increased heat exchanger areas. They elected to have two evaporators instead of one—one evaporator for maintaining freezer temperature at 0-5°F and the other for holding the refrigerator at 40°F for fresh food. Because electric heaters are used for defrosting, they now save additional energy by setting the automatic defrost cycle to every 4 days instead of every 18 hours.
Dishwashers have traditionally required a lot of energy – first to heat the water and then to heat the air to dry the dishes. Although dishwashers are watertight, they don't actually fill with water. Just the bottom fills up. There, the water heats to 130 to 140 degrees Fahrenheit. Then a pump shoots the hot
water up to the jets, where it is forced out through the spray arm. Dishwashers use energy primarily for heating water and secondarily for circulating the water through the machine. New high efficiency dishwashers by companies like Fagor have a more effective washing action, energy efficient motors and other advanced technology such as sensors that determine the length of the wash cycle and the temperature of the water necessary to clean the dishes.
An oven is pretty simple - The Components are a thermostat to regulate the temperature and a timer/clock control. In a non-convection oven, there is a thin layer of air that normally insulates the food. Convection ovens use a fan in the back of the oven to move the heated air around in the oven compartment, distributing it more evenly than a regular oven. Because a convection oven blows the air around, it strips away that thin layer of air, resulting in a faster cook time at lower temperatures.