Do size of holes in drum determine how well clothes spin?

[andyr12345]

I wonder can someone tell me if the diameter of holes in the wash drum determine how much water is left in clothes after a spin or not. 

I have recently got a samsung washing machine to replace or old Hotpoint washing machine - both do 1400rpm maximum speed . - Its just that when I do a cycle in the Samsung washer on 1400rpm spin speed the clothes to me dont feel like they come out as 'dry' as if they were spun in the Hotpoint washer at 1400rpm , both spun at 1400rpm at the same length of time.

More things noticed:
After spinning with the Hotpoint the clothes seem to be 'stuck' to the sides of the drum as well as 'dry'er' - in the samsung they are not stuck to the sides of the drum after the spin cycle is finished.

At some stage of the spin cycle the drum does appear to 'resonate' / hum as the rpm is picking up to 1400rpm , not for long - just a few seconds , but it does not do this in the Hotpoint washing machine as it gets up to 1400rpm

As a guide to see how large the holes were in the drum of the Hotpoint washer i got my drill bits out to see which drill bit fitted the diameter exactly in the holes in the drum in the Hotpoint Washer .

Here are the holes in the Hotpoint washing machine drum:



Then I put the same drill bit into the holes of the Samsung Washing machine holes in the drum and it would not fit , so the holes are definitely (not much) but smaller than the holes of the Hotpoint washing machine Drum (cannot be seen properly in the pic):


Other observance - the holes in the lifter of the Samsung are like 'pinholes' 


Compared to the holes in the lifters of the Hotpoint which are a lot larger, about the same dimension of the holes in the drum itself:


So there you go, I would be fascinated to see what others think. Would the larger holes in the Hotpoint help with extracting the water out of the garments better by centrifugal force better than the Samsung Washing machine drum with smaller holes - or has it no bearing whatsoever at all on the performance of the spin?

 

[Whitegoodshelp (Andy)]

Hello Andy. What size drum capacity were the two washing machines? Drum capacity can affect spin efficiency, with the larger drum being able to exert more centrifugal force.

However, it seems that it's not an exact science and definitely all spin speeds on different washing machines aren't necessarily the same. If you look at the table I have on this article, how drum capacity can affect spin efficiency in washing machines, there are some strange results. Some washing machines have the exact same spin speed and the same size drum and the exact same spin efficiency rating. But some washing machines have a larger drum and the same spin efficiency rating. But most of the drums with larger drum capacity have a higher spin efficiency rating.

I can understand your interest in the differing drum designs, which are a natural concern when you observe the differences in spin efficiency and the differences in the drum design and the holes. If it was just down to something as simple as size of the holes though, I'm pretty sure that all washing machine drums would have the exact same size of holes and the exact same number.

Water is expressed from the clothes by the centrifugal force of them being pressed into the drum during spin. Theoretically, if there were no holes in the drum at all you should get the exact same amount of water extracted from them. It's just that obviously we need holes for the water to drain into the outer tub and get pumped out.

Another issue is that some washing machines with the exact same top spin speed will spin at that top spin speed for less, or longer than others. I remember the old Hoover fast spinning washing machines only used to spin at the top spin speed for about 30 seconds, and even then only if it had decided that the load was optimally balanced.

A lot of washing machines will reduce or even miss out the very top spin speed if the load isn't nicely balanced, and if you have a larger capacity drum this is more likely to happen as it is common for large capacity drums in washing machines to be regularly under loaded. This is due to the fact that the average wash load for the average household is way lower than 7, 8 and 9 kg. Large capacity washing machine drums are ideally meant to facilitate washing twice as much laundry at a time, and therefore saving on wear and tear, water, detergent, and electricity. But most people buy them and carry on washing the same loads as they did before, which is pretty pointless.

[andyr12345]

Hi Andy , thanks for the reply and as usual your answers make sense . 

Both 9kg capacity - I got out the measuring tape and measured the inside the drum (from wall to wall) 

HOTPOINT = 14" (from front to back of drum)  - Diameter = 18"
SAMSUNG= 13" (from front to back of drum) -  Diameter = 20" 

I see what you mean of how much of a long spin - i have noticed on a lot of washing machines myself that they only do the highest speed at the last 3minutes if that - even if they have balanced correctly. Its a shame that for most of the spin (if load has balanced correctly) that they cannot do a good decent spin at 1400rpm for about 6 minutes or more (then i suppose it could crease/damage the garments more could it if it done that?)  

There is not too much difference in water remaining between the 2 washing machines I suppose , I just think after 1400rpm in the Hotpoint they come out with less water left in the clothes. - one plus of the Samsung I am finding is that  (even in a quick wash) that after the final spin has spun the Samsung will revolve the drum a few times before stopping so all the clothes 'flop' down in the drum, whereas on the Hotpoint washer after a spin on 1400rpm the clothes would be 'stuck' to the sides of the drum wall surface when opening up the porthole door and the Hotpoint did not do the couple of drum revolving at the end , the display just said "2 minutes" and just emptied the water out of the drum and then stopped. 

[Whitegoodshelp (Andy)]

I think when a washing machine goes into spin and reaches the correct speed the vast majority of water that could be extracted is extracted in the first 30 seconds. After that there are diminishing returns for the amount of extra water that can be removed.

Another thing to bear in mind Andy is that the chances are an old washing machine will be spinning a bit faster due to the fact of wear and reduced grease in the bearings of the motor and the drum. Also, the colder the weather, the wetter the laundry feels because the temperature of the rinse water is colder and that generally makes something feel wetter.

[andyr12345]

39 minutes ago, Whitegoodshelp (Andy) said:

Also, the colder the weather, the wetter the laundry feels because the temperature of the rinse water is colder and that generally makes something feel wetter.

true that. maybe that's what it is then. am i dreaming or was there some washing machine out once that done a warm / hot last rinse ? - was it made by Haier or someone like that . The bonuses must of been that it rinsed the clothes better was it?