[Default] On Wed, 12 Nov 2008 08:04:23 -0800, "William \"Chops\"
Westfield" <westfw@mac.com> wrote:

>>> front loaders. They use only a fraction of the water top loaders use
>>> (and, if washing hot, only a fraction of the energy). It's a feature
>>> of the principle: instead of filling the whole tub, it is filled only
>>> to some 10% or so for each cycle.
>
>I fail to be convinced.  At the load level WE use for clothes, 10% of  
>the water would result (I think) in a somewhat damp pile of cloth and  
>caked soap.  

Have you ever used a front loader, or observed it in action? Washing
is not equal washing. There are several different mechanisms involved,
and they are different between front and top loaders. If you're
interested, take a good model and really look at what happens there.

Top loaders immerse the fabric in water all the time. Front loaders
never completely immerse. This results in a much lower water, soap and
heat energy use. 

Due to the lower water use, it is common to have more washing and more
rinsing cycles; better machines often use 5 or more rinse cycles and
still use less water than a single rinsing cycle on a top loader. This
results in less residue on the clothes; you know that dissolving five
times in 10 liters results in less residue (without considering the
effect of five times shaking the fabric around) than dissolving one
time in 100 liters. (You also know that the US has an abnormal high
incidence of allergies. Detergent residue on clothes is probably not
something decisive for this, but with allergies it's not one factor,
it's the addition of many.) 

Top loaders create mechanical friction mostly between the plastic of
the agitator and the fabric (newer models with the spiral agitator are
a bit better and try to simulate more what a front loader does). Front
loaders don't really have an agitator (except for some rounded humps
in the drum) and create mechanical friction between the pieces of
fabric. This results in both less strain on the fabric and at the same
time a better mechanical washing action. Clothes washed in a front
loader have a longer life. (Which again leads to less resource usage.)

Due to both the reduced amount of water and the better mechanical
action, the amount of soap required in a front loader can be measured
in teaspoons -- top loaders usually measure in cups :)

> Now, if the load size is supposed to be 1/4 what it is  
>now, so that it can actually tumble, and we have to do 4 times the  
>number of washes...  I guess I believe it will save SOME water, but  
>I'm not sure that it's significant...

I'm comparing same load sizes. Front loaders don't "tumble"; the
clothes are not immersed and don't float in the water. You really have
to see how that works... it's a different kind of washing. 

Have you ever been in a washing saloon? They usually have both kinds.
(But the front loaders in washing saloons are not the best ones, and
neither are the top loaders. Both are usually pretty simple
representatives of their kind.) You can see the principle, even though
you can't see the finer details of a good front loader's washing
cycle.

Gerhard

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist