Solar Heated Water for Washing Machines with a Cold Feed only.

[Paulh_Boats]

oops wrong button!
what I was trying to say was,locate the sensor responsible,set it up with the temperature you want the brain to think its reading,measure the resistance,now,replace the sensor with a resistor of that value.....worth a try?

Could be worth a try but then you could not use a hotter wash - important occasionally if you have kids clothes to wash. And for a single feed there is still the problem that you waste warm water on the rinse cycles which use the majority of water.

Do they have a large installed base of solar thermal in Germany? I would expect so having stolen every cheap PV panel  . In which case I'm surprised Bosch and/or the Green Party have not produced or encouraged a solar friendly washing machine.

-Paul

[David]

The older washing machines with hot and cold inputs only uses hot water input for wash settings higher than 60C,

My "older" Hoover washing machine takes in hot water for all washes. However, on the coldest washes it takes in little water from the hot water pipe. On the hottest washes it takes in the majority of water from the hot pipe. Between those it takes in about the same amount from both pipes.

One way to get it to take in more hot water than it would otherwise do is to use the economy button. This drops the temperature of the wash to the next lowest setting. A "50C" wash with the economy button pressed is carried out at 40C. This uses the heater for a lot less time than using the 40C wash button (there is a heater lamp on the machine and I am occasionally sad enough to watch it:-) It also uses less electricity than a 30C wash. I'm certainly not increasing my electricity consumption by following government advice to wash everything at 30C.

My small dishwasher also makes the dishes just as clean when fed with hot water rather than cold.

[odbob]

Hearing all the comments, it is still down to the manufacturers to produce a machine which will encompass alternative sources of heat and until they achieve this, they should not be labelled "A" rating.

It is not right that they can cheapen down on machines by hiding behind various obscurities such as low water consumption / length of pipes etc, if they are to deserve "A" rating then they should be at the very forefront and should assume everyone is doing their bit to improve systems

I would give them a "D"

And what about dishwashers, whats their excuse for cold fill only?

[Paulh_Boats]

odbob,

Dishwashers are a thermal nightmare.

There is such a large mass of steel enclosure (uninsulated), crockery and cold water in the sump that any incoming hot water is quickly cooled. Even filling with water at 70C last summer I stopped our machine and the sump water was barely hand warm. The drying cycle heats the crockery with the electric element alone. Ideally that cycle would use MORE hot water to get the crockery hot.

They will need a radical re-design to be solar friendly and with 99% of houses not having solar its unlikely to happen soon.

Having thought through the physics I think a humble washing up bowl is the future.


This is perhaps another case for the mixed technology approach... use the machine during the day when the solar PV is producing its maximum output or whenever the turbine is spinning.

[renewablejohn]

Mickey

We installed our new cold fill washer into our hot water supply and it worked perfectly until the hot water tank reached approx 60C it then stopped never to start again. Called out the engineer who inserted a new electronic board. Since then been on cold fill only but it does seem a waste of energy.

[O MidKnight]

Many years ago...

I disconnected the immersion heater from my hot and cold washing machine

I run off the stagnant water from my 15mm supply pipes into a bowl from the nearest tap

When the solar cylinder reaches 40C approx I do a 40 wash

When the solar cylinder reaches 50C approx I do a 50 wash

Effort required but good savings

[David]

There is such a large mass of steel enclosure (uninsulated), crockery and cold water in the sump that any incoming hot water is quickly cooled. Even filling with water at 70C last summer I stopped our machine and the sump water was barely hand warm. The drying cycle heats the crockery with the electric element alone. Ideally that cycle would use MORE hot water to get the crockery hot.

It does depend on the dishwasher. Mine is small and so there is little cold water in the sump and enclosure/dishes to heat up. A fill up with hot water is enough to warm the thing through on the first rinse. The heater hardly runs on subsequent wash and hot rinse cycles. It does not have an air drying cycle.

Overall it does not consume a lot of water compared to a sink full of water. Neither does it have a large electricity consumption on hot fill. Programmes also finish much quicker on hot fill.

A large dishwasher in another branch of the family also runs much more quickly on hot fill. Its computer appears to estimate running times based on cold fill initially, but as it senses the water temperature its estimate of running time goes down dramatically. Sadly it doesn't display a rapidly tumbling time estimate, it just suddenly goes from over two hours to at least half an hour less.

[Paulh_Boats]

David,

Thanks - it sounds you have better model than our Bosch Classixx.

What is the model name of your dishwasher?

cheers
Paul

[David]

It is a Zanussi table top model. However, as it is something like 15 years old it may not give a reliable guide to modern ones.

[Mickey]

Thanks - some excellent information & suggestions.   From what renewablejohn says I could be in trouble if the Solar feed gets above 60degC.    So I'm looking to a solution based on a mixer system where I can set the feed temp to the washing machine at around 40degC.    Has anyone any suggestions on a reliable mixer product I can buy??

By the way what machine have you got renewablejohn ?

Mickey

[billi]

Do they have a large installed base of solar thermal in Germany? I would expect so having stolen every cheap PV panel  . In which case I'm surprised Bosch and/or the Green Party have not produced or encouraged a solar friendly washing machine.

-thats the reason they sell pv so expensive there , because of the grants....

paul the former green party did not sleep with the industry and the industry did find other markets  , i am not here to present germany in the eurovision songcontest...

like we all know there is not a lot of intest into good products or renewable ones ,because of the market idea... and the structure of it, it all has to be sellable or affordable..

there are too little concepts for the way inbetween those both !

its absolutely poor design of washing or dishwashers  are not able to cope with that
or free energy that was produced


Donot think that Bosch still produces in germany a lot (can find out) 


like said i know of three or four options


-mixing valve
- proper controle automated system (150 pounds but might still work after machine broke down)
- just add in 15 liters of hot water before the wash manually
-self build

you have problems... . mine is freakin out when the generator runs ... so have to wait untill the sun comes out to use the free  pure sinewave inverted energy ...

cheers billi

[Paulh_Boats]

We used to have a simple Hotpoint washing machine with one rotary knob and an Economy switch. With the Economy switch on it would take hot water at any temperature without heating it.

It would have been PERFECT for a solar water system with a mixer set at 30C, but after replacing the motor brushes, belt, hinges, pipes and even the drum bearings I called it a day after 18 years of service!

Now we have a fancy modern microprocessor model that has a mind of its own and stubbornly heats with electricity to 30C - there's progress for you. 

[Ivan]

They're definitely not built like they used to. Our previous - Philco, affectionately called 'Billco' was inherited from my grandfather, and worked for a couple of decades. I think we put about three water pumps in over the years, plus seals etc. Finally replaced due to casing rotting through (I even repaired this with car rust-inhibitor and white spray paint, but eventually even this was not enough).

New machine is about three years old, and has been repaired twice (1- pressure sensor failure, 2 (today) - heat sensor). I was talking to the repair man about this thread, he said that there's no way of fooling our machine. He agreed the only chance you'd have is feeding hot water into the cold fill, as well as the hot fill, but even this would set off a fault (which terminates the wash) due to the fact that the cold water is out of spec! You can't disconnect elements (causes fault), can't emulate the heat sensor with a resistor (causes fault due to heating time being out of spec) etc.

He says our machine takes only cold water for all washes up to 60C! I'll get a powermeter on it over the next few days, and experiment with hot washes/cold washes to see which uses more/less power.

[Paulh_Boats]

I have just contributed to this blog thread:

http://www.whitegoodshelp.co.uk/wordpress/whats-happened-to-the-hot-water-valve-in-washing-machines/#comment-2838

Its run by a repairman that does reviews of washing machines. He says quite a few manufacturers read his blog. So if we all bombard them with the good news about solar heating things might change!


-Paul

[Ivan]

Great find! I'll have a read, and see if I can slip something in.

The repair man I spoke to, who seemed to be quite clued-up on the subject, said the main reason is that many people's plumbing is too long to allow any hot water in, as there is too much dead volume in the pipework. I can see this point entirely, but I've deliberately sited my washing machine in a really inconvenient place to take advantage of the shortest pipe run. I also religiously run the hot tap (as does my wife) immediately prior to turning on, to ensure that the cold water has been flushed out of the pipe (takes approx 30seconds). Having read this thread, and done further follow-up, it seems all this effort is completely futile. What's more, we tend to avoid the very hot washes to reduce energy consumption - so I bet my hot valve has never openned anyway! I'm thinking of swapping hot and cold valves over -see what happens!

I reckon a solar-ready washing machine, dishwasher etc would be a good seller. I'd buy them, for a start!

My thoughts are thus (for solar-ready washing machine):

1. Design new washing machine, based on standard mechanicals
2. Add a wireless sensor attached to hot output of hot water tank - gives washing machine feedback on actual hot water temperature
3. Prior to filling, the washing machine drains hot water to waste until hot water at washing machine is within 5C of hot water measured at wireless sensor, unless say 120seconds has passed, in which case, the bypass-to-waste is aborted (avoids draining unnecessarily large volumes of water in the event of a failure)
4. If hot water temp at washing machine exceeds hot water at wireless sensor by 10C, error alarm flagged
5. If wireless sensor detects cold water (say under 25C), then no bypass-to-waste operation
6. If wireless sensor detects lower temperature than intended wash cycle temperature, then machine is filled entirely with hot water, unless higher temperature is detected during period of fill
7. If wireless sensor detects higher temperature, then appropriate amount of cold water is fed in at same time, temperature of drum is noted, and cold water feed adjusted to compensate.
8. Water heater elements included in design but their operation is selectable by switch on front of machine.
9. If cold water-to-waste is unacceptable (I can see water regulations being a problem here), then the water could be retained inside a mini-storage tank in the belly of the beast, to be used up for cold rinces at the end of the cycle.
10. Other features - insulated drum?

There, I reckon that just about covers everything. Anyone care to add or change? I bet we could come up with a really good machine between us! ('Navitron Solar-ready Washing Machine'?)