Does Cycle Time Really Matter

[cleanclothes]

Okay. I need opinion's here. When it comes to frontload washers, does cycle time really matter? Also, what is the big deal about an internal heater?

Thanks for all of your opinions.

 

[peterh770]

Doesn't matter, as long as it gets the job done.

The internal heater is helpful because the small amount of water in the washer can quickly cool down. Some FL's have a very long wash, so the water that entered the machine as hot is cold by the time it drains. So a heater will keep wash water nice and toasty. Also, because there is so little water, it can be heated to higher-than-tank temperatures relatively easily.

 

[westytoploader]

It depends on the machine and how much water it uses. I've used Dexter, Wascomat, and Huebsch (SQ) commercial coin-ops for comforters and other large loads, and they pretty much fly through a cycle in 30 minutes. I have a 1993 Westinghouse FL and it runs fast as well, even on the "Heavy Soil" setting.

IMHO, the long cycle times on today's FL's are because of the amount of water. With clothes splashing and sloshing around in 4 inches of sudsy water in a drum with large vanes and frequent reversals (double-loader) rather than slapping against the tub, it obviously takes less time to get the job done. Not one load I've pulled out of a double-loader came out only semi-clean.

How I wish they would make the Westy design again...

 

[foraloysius]

Well actually...

Yes, it does matter. There are four factors that are important in the washing process:

1. Mechanical action
2. Chemicals (water and detergent)
3. Temperature
4. Time

These four things have influence on the washing result. If you decrease one of those factors you have to increase one of the others in order to get the same result. Ofcourse you can't take one totally away, because you won't have a process at all. So time is indeed in important factor, not only in a frontloader, but also in a toploader. That's why a heavy cycle is longer than a light cycle.

I'm sorry to disappoint you again Austin, but a lower water level is really better in a frontloader. Washing in a frontloader is a bit like the oldfashioned way of washing by beating clothes on a rock. When the clothes fall down in the tumbling process in a frontloader they need to fall on the drum, not in the water. The stone in the old fashioned process was not in the water but above the water level. The laundry was saturated and after that beaten on the rock. That was repeated over and over and that how laundry became clean. Extensive research have proven this and that's why modern frontloaders with low water levels in the wash cycle get clothes cleaner than their high water level counterparts. I know the older ones are more spectacular to look at, but the newer ones really clean better.

 

[westytoploader]

Hi Louis,

I understand what you mention about a low water level being better in an FL, however, this is what really confuses me. When I washed a load in the Bendix (splashy FL), some of the shirts remained stained, so I can understand how the "rock-beating" principle would work better (of course the Bendix's drum turns too fast for that). But when I do a large load in a double or triple-loader coin-op at the laundromat that also fills high, everything always comes out clean, which is really puzzling because you mentioned that a high water level wasn't as effective. I'm thinking it has something to do with the large size of the vanes and the reversing drum, but how can a load in one FL come out cleaner than a load in another if both basically fill and wash the same?

--Austin

 

[foraloysius]

Those large vanes might indeed have influence here, they might increase the mechanical action. Perhaps they work more or less like an agitator in a toploader. BTW, a reversing drum, or tumbling both ways was common here in Europe right from the beginning of the frontloaders here. I was really surprised when I saw that the older American frontloaders didn't do that.

To answer your last question: it might look that two washers fill and wash the same, but only small differences can have influence. A vane that is shaped a bit different, or more holes in the drum. A somewhat bigger drum, a somewhat lower water level. Longer wash times, or slightly hotter water, all these factors have influence on the effectivity on the water.

Louis

 

[launderess]

What one wants is a drum with a large enough diamater and "vanes" to lift and drop loads of laundry to achive the "rock beating" effect. Good washing action lessens the need for long wash cycles .

If one watches a commercial/laundrette washer, when they are loaded correctly laundry moves from 11-4 and 1-7, falling a nice height and "smacking" against the drum. Many home front loaders are more concerned with using their paddles to "scoop and shower" water than raising and dropping laundry, IMHO. You hardly ever see perforated fins on commercial front loaders, but rather sturdy solid SS fins.

Launderss

 

[launderess]

And Furthermore

Washing rythyms also factor into cycle time. A good heavy wash cycle, that has more rotations with fewer and shorter pauses will clean better than one that has fewer rotations, with long pauses.

Again using the "beating laundry against a rock" theory, the more aggressive one is about slapping the laundry about, the faster soils will be removed.

Launderess

 

[Designgeek]

Some factors I think are also relevant:

One is the depth of the load relative to the axis of rotation.

If the load is at or below the axis of rotation, you get more lift-and-drop action, and also you get overt mixing, i.e. relative movement (movement of garments relative to each other). Each piece has a chance to get to the surface of the load and drop/slide across to the bottom.

If the load is significantly above the axis of rotation, the drop is less, and you get stratification rather than mixing (no relative movement). Some pieces, the ones in the center of the load, just revolve about an axis that is represented by the center of gravity of the load; they do not scrub or lift & drop. As well the water does not move as much relative to the clothes; some pockets of water may simply go around in circles rather than moving *through* the clothes.

Two, the overt diameter of the drum, and acceleration of falling objects due to gravity. In a smaller drum, a given garment falls a smaller distance, picks up less momentum as it does, and therefore has less opportunity to have water/detergent moving through it as it gets squeezed and released by its own weight and the weight of other items.

In a larger drum, there is a larger distance to drop, therefore enough of an increase in the momentum of each piece falling as it's lifted & dropped. Therefore more of a squeeze at the bottom, and more of an opportunity for water to circulate during the repeated squeeze-and-release of the rotation. As well, the weight of a larger load produces more squeezing-out of clothes at the bottom, so they can re-absorb more water/detergent as they are brought to the top of the load.

Also, if the reversing of direction occurs too frequently, it will interfere with the "mixing" action by reducing relative motion as per my first point. There needs to be enough rotation in each direction to allow each part of the load to be brought to the surface at least once before reversing direction.

This in turn gives me an idea for the design of a drum that will maximize the relevant actions & motions. (Note to self: double-cone horizontal drum with converging blades.) I'll go into more detail in one of our "invent a better washer" topics.

 

[foraloysius]

You are more or less right. But the drumspeed is also important. A fully loaded European frontloader can still have a decent wash action due to the fact that the drumspeed is that fast that the clothes still drop at a 5'o clock position. And I don't think it is really necessary for all the parts to hit the surface at least once before reversing action. As long as all the parts eventually get the same treatment everything will come clean.

 

[Designgeek]

Yes, you're right about speed of rotation; silly me for not mentioning it because I know about this one. Smaller drums tend to be rotated faster; larger ones, slower. The thing to watch out for is to avoid having stuff stick to the drum all the way 'round rather than dropping off at a reasonable point.

Where less water is used, the load is less "sloshy," and therefore a slower rotation speed should be used.

For this reason, one of the features I think would be majorly cool on one of the machines we-all are designing here, would be a continuously variable speed control for rotation. You'd look through the window and adjust the speed to get the best lift-and-drop action. You could make notes of the settings you used, so as to dial up the appropriate speed depending on the load.

However the tradeoff is that the higher the position from which clothes are dropped, the more impact they have when they fall, therefore a need to beef up the suspension system to cope.

 

[foraloysius]

My Miele uses several speeds in one wash cycle. It actually starts half way one rotation. It begins at 40rpm wich is intended for saturating the clothes. Then there is a pause to let the water get into all the fibres of the clothes. After that pause the drum starts rotating the other way at 55rpm which is the actual washing phase. After a while it goes back to 40rpm again to saturate the clothes again. So there is really a comparison to beating clothes on a rock LOL.

 

[Cybrvanr]

internal heaters

Internal heaters are a godsend to the people that have long runs of pipe from the hot water heater. A problem I face in my kitchen with the dishwasher is that I need to run the faucet till the water gets hot before starting the dishwasher. If not, then the first cycle gets cold water. In a washer, it will fill with cold water, even though hot is selected, because the washtub has enough water in it before the warm water gets up the pipe

 

[Designgeek]

That "cold water before the hot" is sometimes called "purge water." One of the graywater systems I'm designing, saves that water in a "clean" tank and uses it for some or all of the laundry wash-water.

Foraloysius, interesting combination of speeds there. What's the diameter of the drum?

I'm thinking it would be interesting to compare drum diameters and rotation speeds, and also put that information into the online centrifugal-force calculator to get G-force information, and then compare. I suspect there will be some convergent outcomes here.

 

[foraloysius]

It's hard to measure, but approx. 47 centimeters.

 

[foraloysius]

G-force calculator

Here's the link to a G-force calculator. I measured 47 centimeters, so the radius in millimeters is 235. With a rotationspeed of 40, the G-force is 0.4. At 55rpm, the G-force is already 0.8.

I also calculated that at top spinspeed, 1400rpm, the G-forces are 515.

http://www.jouaninc.com/gforce.htm

 

[peterh770]

Louis,
Does your Miele do the 7 seconds at 40 rpm, 7 seconds at 55 rpm, pause and reverse, doing the same routine? On my Cotton cycle, the first 5 minutes are at 40 rpm, then the next 30 minutes are with the 55/40 routine, and the last 15 minutes are at 55 rpm.

 

[foraloysius]

Peter,

Mine is a little different. My Miele is from the first Novotronich generation. It tumblens the first five minutes indeed at 40rpm for 10 seconds and then a pause of 5 seconds. After that it tumbles at 55rpm for 7 seconds then slows down to 40rpm for 4 seconds and then a 4 seconds pause. That goes on until the end of the main wash. Every routine is also 15 seconds.

Here some figures about the final spin cycle:

90 seconds on 900rpm: G = 212.8
90 seconds on 1100rpm: G = 317.9
3 minutes on 1400rpm: G = 515

 

[Designgeek]

Most interesting! 1G during wash, and up to over 500G during spin.

I'm going to get back to this topic in more detail over the weekend when I have some free time, this has all kinds of interesting ramifications.