@rolls_rapide
That's PowerWash 2.0 for you.
You see, the most inefficent part about EU washers is heating up the water.
You reduce the usage for heating water by reducing the amount of water in need of heating up.
And, to be frank, manufacturers have optimised those amounts of water for traditional washes to the extreme.
You can't really just drop the water level any more without causing other issues.
So, Miele took a verry interesting approach to the entire thing, not unlike the Fisher&Paykel EcoActive system:
The idea is that you first heat up the minimum amount of water, let that do the chemical action, then dilute out and dissolve away the already loosend dirt.
So, instead of doing chemical action and dilution in one step with one water level needing to heat up the enitre amount of water needed for diution, you split dissolving of dirt by chemical action and diluting it away into 2 wash stages.
On these machines, this works as follows:
At first, the machine flushes in detergent with a minimal amount of detergent (2L in most cases).
Then, it switches on the recirculation and does its first spin up.
During that it measures the weight of the laundy.
If the laundry weight is in spec (somewhat less than a full load by weight), it decides for a PowerWash 2.0 cycle.
With that, the Spin&Spray procedure starts.
For that, it repeats these steps several times (5-10 times, depending on load size):
1. Fill: It adjusts the water level, usually in 2-3 liter steps, as necessary.
2. Slow tumbles: About 2 in each direction without recirculation.
3. Spin: Recirculation switches on, washers spins up to about 600rpm, slows down and just before stopping cuts off the recirculation.
This procedure spreads the highly concentrated detergent solution evenly about the load.
At the end of this, the laundry is damp to wet, evenly, but not dripping.
Now, while tumbling slowly, the recirc is switched on one last time to dump the water from the sump onto the load.
For example, for a load of a weeks worth of socks, TShirts and underwear (about 10 pounds or so), it needed 8L for this.
Now, the first part of the mainwash starts: Heating and agitation.
The washer now switches on the drain pump for about 30sec to get the sump to a known level.
Technicly it drains, but haven't heared it drainig away much if any anytime I watched this stage so far.
Then it fills with a metered amount of water (2l; so 10l total in my example) that is just enough to cover the heating element, but not to reach the tub.
(It checks its level switch for a correct reading to ensure the water does cover the heater but does not reach the tub.)
Now it heats that little amount of water to boiling.
The steam heats tub and laundry and thus, detergent gets activated.
This heating takes not verry long, like 20min or so with the heater pulsing on and off.
After that, the load just tumbles, gets agitated, and once the sump water temperature drops enough, it tries to recirculate once in a while, but dosen't manage to because the level is to low.
After a usual main wash time, the second stage happens: Dilution.
Now the washer fills to a normal wash water level (for the load in case that was to 15l total).
And washes along for like 20min like a normal cycle with recirculation but does not heat anymore.
Then drains and rinses as usual.
That first stage activates enzymes and bleach in the detergent.
Everything gets dissolved into the tiny amount of water in the load.
The second stage dilutes the dissolved dirt and water out of the load so it can be drained away.
The result: My example load washed just as clean and rinsed just as well as in a normal washer, but yet didn't use more than 600Wh (and 76l of water total for 4 rinses plus wash).
To take Mieles data on that:
For a machine of the same generation and the same max load, usage data is as follows comparing conventional vs. PowerWash 2.0:
For a half load on the 40C Eco cycle, both use 39l of water, yet one uses 530Wh, the PW2.0 only uses 340Wh.
On an full load of Cottons at 60C, both machines use 1350Wh.
On a partial load, the conventional system uses 1150Wh, the PowerWash2.0 uses only 1000Wh.
On some other cycles (for example, a normal half load on Cottons 40C), there is no labeled difference.
Yet on Automatic Plus, for a 6kg load at 40C (which will run the PW2.0 course, so that seems to be about the upper level), the difference is 800Wh vs 600Wh, so 25% savings, while takeing the same time, giving the same results and using the exact same amount of water.
[this post was last edited: 10/24/2019-09:26]
