Washing machines are most efficient when operated with full loads of laundry. Only 10-15% of the energy used in washing a load of laundry goes towards operating the machine, the rest is used to heat the water. Simply put, if a load of laundry isn't washed in cold water, 85-90% of the energy used goes toward heating the water. Because the same amount of energy and water is used whether the machine is full or not, significant amounts of both are wasted if a small load is washed at the full setting.
Clothing Weight: Front loading washing machines can hold as much as 18 pounds of clothing. So how many items are in a pound of clothing? One way to find out how much your loads weigh is to weigh yourself holding a load of dirty laundry and subtract if from your weight without it. While weight varies with type of material, here are a few general guidelines: 1. A Twin X-L Comforter= 3-5 lbs. 2. A Complete Outfit for a Child= 1-3 lbs. 3. A Complete Outfit for an Adult= 3-5 lbs.
Clothing Size: In addition to the weight of laundry, there are also size/dimensions to keep in mind. The best load of laundry is one that mixes items of varying sizes. This allows clothing to move more fluidly in the washing machine and keeps the clothing fully washed, fully rinsed, and undamaged.
Fact: On average, washing full loads of laundry can help you go green because you'll use less water and energy per pound of laundry. It is estimated that you can save about 3,400 gallons of water each year just by washing a full load of laundry. Going green has never been simpler.
**Sources: greenyour.com "Wash a full load of laundry"; About.com "How much Laundry is a Full Load?" By: Sarah Aguirre