Volume vs weight
Hi All,
I have been following this thread with great interest. I wanted to scan my very old 1960s Miele laundry brochure which featured both their top loaders with agitator (yes Miele did make them) as wringers as well as their front loaders but it has gone missing

Anyway from memory this is what the Miele philosophy between the two systems was:
The top loader with agitator needed 15 litres per kg of washing so the laundry could move around freely and be washed properly. So a toploader with a drum volume of 90 litres could handle 6kg of dry laundry.
With a front loader the principle is similar, but because of no agitator the machines weight to volume ratio changes to 10 litres per kg of washing.
I think many consumers of front loaders as well as top loaders are being taken for a ride. Yes, they can hold and wash their claimed capacity, but many manufacturers are just putting in more in the same space and extending wash times to compensate. Many wash programmes for the energy and water label are exceeding 4 hours in frontloaders! I think there is going to be a modification to the AUS standard to state a maximum wash time of no longer than 3 hours. This change in the future may see ratings on the same drum volume decrease as they may not be able to meet the cleaning requirement in a lesser time, so lowering the load size would be the only option, otherwise they would need to increase energy and water consumption.
Therefore the traditional 15 litres and 10 litres per kg of washing doesn't apply anymore.
In Australia and in Europe manufacturers are using the same drum volume and rating it at different capacities. A 50 litre drum is being rated up to 7kg and a 78 litre drum up to 11kg. All they are doing in this scenario is dropping the ratio to 7 litres per kg.
What the DOE is doing in the US is to standardise this ratio somewhat, but are not distinguishing the volume to weight ratio of the different systems.
If they did the same in Europe with drum volume it would be a similar story. I think all manufacturers of front loaders should state the rated volume in litres as well as its claimed capacity. This would give more transperancy to the consumer, like in the US.
With the new energy label in Europe, Miele has changed the Cottons programme to make it more energy efficient, but in doing so has had to increase the cycle time by 40 minutes. So now a Cottons 60 degree programme for 8kg takes 2 hours 59 minutes instead of 2 hours 19 minutes.
So you can see it is a real balancing act to get the right ratios of time, water and energy consumption to get your clothes clean.
Cheers
Rod