OT: washing machine question

This has nothing to do with electronics but I know some pretty bright people with interesting backgrounds hang out in here. Now that I'm done buttering you up, here's my question:

Why is the drain system of a washing machine above the water line of the tub? In other words, why is there a pump when all you need is a drain hole in the floor and a solenoid controlled valve in the machine?

Don't tell me it's to prevent leaks, the hoses that connect the tub to the pump can leak too (as I've discovered).

Reply to
a7yvm109gf5d1
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On ours it isn't.

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Regards, Joerg

http://www.analogconsultants.com
Reply to
Joerg

What kind of washing machine is it? Here in Canada, the bog-standard thing you get in a house or apartment that has a washer/dryer place, there is a drain hole in the wall at about 4 feet high. The hose from the machine has a J at the end of it, and you just hang it in the drain. There is no seal or anything. So you need a pump to empty the tub. I've never seen a washing machine that drains the tub from the bottom to the floor in normal operation. It just strikes me as odd.

Reply to
a7yvm109gf5d1

Just in case you don't have a drain on the floor handy. They're not always available, and it would be a royal PITA if you found it it was a non-pumped drain washer AFTER it was unpacked and shoved into place.

AND there's the recycled soapy water feature (suds return?) some may want to use. Can't do that unless you have an external tank.

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Linux Registered User # 302622
Reply to
John Tserkezis

Yeah but when they build a house, they're putting in a drain anyways. Why isn't it standard to drain towards the ground?

Somebody had to make a standard a long time ago, why choose the pump?

Don't know what that is. Elaborate please. The only reason I'd see for a pump in a washer is the good old GE Filter-Flo system which recirculates during the wash cycle so the lint ends up in a lint trap. Strangely enough, I can't find any new machines with this feature. Nothing makes me happier than picking up that little ball of lint after a wash cycle. Newer machines just leave the crap, hair and lint on the clothes. I'm just trying to see if it's possible to save resources by using less energy to drain the machine and use fewer resources building them if you don't need a pump. It's a mystery to me.

Reply to
a7yvm109gf5d1

Lots of people have the washing machine in the basement. In general, the sewer line enters the building several feet above the floor.

Tam

Reply to
Tam/WB2TT

Not round here they don't. (Australia) Not for any specific reason that they simply just don't.

Because the ONLY drains of this type I've seen in the laundry room, was requested by the owners during building (if they had that option). And this was just to drain water that was spilt, never seen it designed as a washer drain port.

It's a feature that expels used (soapy) water into your laundry tank, and is sucked back in for your next load. Saves water that way, though probably only really useful if the loads (or at least the first load) was not very dirty to start with.

Probably economics. If they can save 10c per unit during manufacture, then they WILL save 10c per unit.

Any features added will be gouged out of the customer. Features added via firmware alone are even better. 0c per unit cost, and big dollars increase on retail.

No feature will be added unless their marketing people think it's a selling point AND customers are willing to pay for it. Dearly.

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Linux Registered User # 302622
Reply to
John Tserkezis

If you use a solenoid valve, it has to be large, and it has to be able to seal tightly year after year, sock after missing sock (joking!), lint, coins, laces, etc.

Using a pump(often low cost due to the fact they usually run off the main motor via some sort of engagement mechanism) has the advantage that water does not come out unless it is running. A pump generates a significantly higher pressure, thus requiring a smaller hose, lint gets blown away, and a simple trap catches the heavy stuff.

Using a pump also allows most people to use the washer in the basement, where the main sewer drain may be a few feet off the floor. It would be costly to stock two different models so one would have a valve drain and the other having the pump, not to mention customer confusion and related costs.

Reply to
Jeff L

I don't know if there is a specific single reason, but there are some factors that apply:

** The typical "u hook" drain hose allows easy installation where a laundry sink exists - just hook it over the edge of the sink. ** The "u hook" drain automatically provides a vacuum break so that waste water won't be drawn out of the house waste pipes ino the machine. ** No need for a plumbing connection to a floor drain

Ed

Reply to
ehsjr

always

non-pumped

want to

Likely too expensive to implement now, especially since the majority of people buy things based on the cheapest price. Other possibilities are people likely never cleaned them properly, thus leading to complaints - such as why is my washer leaking all over the floor. Other washers may just send the lint out the drain.

When the pump is running, it is not drawing much energy from the motor, thus the unit is using little energy at the time. Also, what if the drain could not get rid of the water fast enough and the unit had to spin longer to drive the water out - that would waste more energy since spinning uses a lot of energy, and if the cloths were not as dry as they could be because of that, an electric dryer uses a ton of energy to basically vaporize the remaining water.

to drain the machine and use fewer resources building them

The pump is quite simple, lasts a long time, and needs few resources to build, and usually runs off the main motor, some times in reverse for when it's not needed, or for activating features as you mention above. To pump the water out, the main motor is started in reverse, or an solenoid engages a mechanism to make the pump run. A valve likely wouldn't be any simpler and has disadvantages as mentioned in my other post.

Reply to
Jeff L

I certainly don't want a sewer pipe *entering* my building! :-)

Reply to
Jeff L

Where do you think your toilet goes to?

Every drain in any house (at least here in australia) joins up with the sewer line. They all have S-Bends to prevent possibility of smells.

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Linux Registered User # 302622
Reply to
John Tserkezis

It's a siphon break to isolate the machine from the sewer system, hence the stiff J-hose to standpipe arrangement. The standpipe must also contain a "trap" or solid slug of water to prevent sewer gas from entering the dwelling. The pumps are almost all centrifugal and direct drive. Spin it in one direction and it's a low resistance load with no pump action, reverse the direction and it's a high capacity discharge pump emptying the tub much faster than a gravity feed.

Reply to
Fred Bloggs

I think he was making a play on words, referring to water pipes entering the house and sewer pipes exiting the house -- the play on words being based on conflating the "direction" the pipes go with the dieection the contents of the pipes go.

Sort of like correcting someone who mentions a sunrise by pointing out that it is really a horizonset...

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Guy Macon
Reply to
Guy Macon

No they aren't. I'm currently in the process of building a house, and there are no ground drains because they need too much vertical space.

Because hardly any house I've seen has a ground drain (except in the basement maybe).

Because it can be used in any house, in any apartment, and not just in those few places that have a ground drain.

Do you have the slightest idea what percentage of energy consumption of a complete washing cycle goes into the drain pump?

I knew you didn't. Also try to come up with a reliable, large-aperture water valve that doesn't require any appreciable pressure to operate and is cheaper than a primitive drain pump. Good luck.

robert

Reply to
Robert Latest

you left out "and doesn't leak ever - even when lint, buttons, coins etc get lodged in it".

Reply to
budgie

It's a regular Whirlpool. Drains out the back but at the bottom. Same wall drain here, way up, and that indeed doesn't make much sense. I gues it has to do with cost. If there was a floor drain (not always possible in houses on slab) you'd need a valve. For a high drain (like into a sink or wall) you need a pump. To cope with both situation you'd need valve plus pump = more $$$ for the machine.

--
Regards, Joerg

http://www.analogconsultants.com
Reply to
Joerg

ehsjr wrote in news:dz4Ei.13660$5x2.2999@trndny07:

Floor drains may be connected to storm sewers, where you don't want to dump washer grey water.

Reply to
Gary Tait

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