Clothes Washers - Internal Heater Advantages ??
[Information first posted in the Appliances Forum by Alice (Alice_61) on 13 October 2002 - thanks, Alice!]:
Most front loading washing machines include an internal water heater, for good reason. It has many advantages:
1. A front loading washer uses much less water (~5 gallons) for wash portion of the cycle than a conventional top loader (~20 gallons). Consequently, heat loss in the pipes and by conduction to the washing machine become a larger fraction of the total heat available in this smaller amount of water. For instance, with a water heater set to 117F and the hot wash setting for the unheated FriGEmore [see FAQ article, "What is a FriGEmore ??"], the wash water after filling is 95F. With a water heater set to 110F, the wash water is 85F. Wash times in front loaders tend to be longer, which also increases heat loss. A clothes washer with an internal heater allows one to keep the water heater set at a safe and economical temperature (under 120F) without scald protectors and still have sufficiently hot water for thorough cleaning.
2. An internal water heater allows the washer to do a profile wash. The washer fills with cold water and then heats it as the wash tumbles. This gradual raising of the temperature allows protein stains to be removed at a low temperature, avoiding setting by higher heat. Then as the water continues to warm, detergent enzymes work at their optimal temperature and color safe bleach becomes more effective. At high tempertures, odors and oily stains are most completely removed.
3. Front loaders with internal heaters allow a maximum temperature of 130-205F (figures for Neptune and Asko respectively). These high temperatures are very effective at removing tough stains and whitening laundry without chlorine bleach.
4. Detergent is more effective at a higher temperature. The use of sufficient heat reduces the quantity of detergent needed. This reduces detergent cost and also reduces the amount of detergent that needs to be removed from the laundry during the rinse cycles. This will reduce the final amount of detergent residue in the laundry.
5. Soaking is also very effective and economical with an internal heater. The laundry can be allowed to soak or stand for an extended period, then the soak water can be heated for the main wash, if desired.
6. It can eliminate the heat loss in the hot water pipe to the washer. It also can reduce the water heater burden (although the much smaller volume of water used by a front loader makes this much less of an issue than with a top loader).
[first added to Appliances FAQ: 21 October 2002]
[added to Laundry FAQ: 21 May 2003]