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

[heatherw]

Can't you just put it on cold wash and then fill from the hot tap? I don't see why you have to disconnect anything,

[Ivan]

The problem with doing that is that the cold rinses will become hot rinses, thus using an excess of hot water.

[wookey]

How hard is it to nobble the heater?

Having discussed this with the missus, I discover that our heater actually stopped working some months ago so we have been doing ambient-temp washing for quite some time now, and it seems to work fine. The only prob is a) the need to do a hot wash every 3 months or so to get the worst of the gunge out otherwise it wees itself more than usual, b) the fact that it stops twice waiting for the temp to rise and will sit there forever until you give it a reset - this can be simply be deemed to provide useful soaking time, and also explains my comment about our washes taking several hours.

So I can confirm that ambient temp washing does indeed work :-)  (can you tell that I'm not in charge of the washing machine in this household :-)

[Ivan]

Older washing machines are much more forgiving. Mine is about three years old -it recently had a thermostat fault (indesit), which effectively means the heater doesn't function. Result is: Machine has a fit and simply aborts wash cycle regardless of temperature or cycle selected. Now if the Government introduced legislation to make the manufacturers liable for my laundry costs in the event of minor faults causing complete machine failure, I think we'd have more reliable equipment

[stephen]

Miele make a machine that can choose between grey water washing and mains so why not the same with hot water

Stephen

[Ivan]

Is that in their standard catalogue? Have you got the model number? I did look at Miele, as they do make quality stuff, and I wondered whether I'd need to replace our machine during it's heart bypass operation. Luckily not, but Miele would have been the manufacturer of choice.

[pmacantu]

Hi,  I went into harvey Norman looking for a dual input dishwaher.  None available.  the assistant told me that his manager siad that the cold input was more energy efficient.   the merits of that are whatever.  But most dish washers use 1.1KW per cycle which is about 15 Cent here in Ireland.  So I would suggest that wash what you can by hand and if you have no time use the dishwasher.   That is a good as it can get.
With the washing maching,  I would put a thermostatic valve on the input set to say 25degrees,  so the internal element has less work to do,   and you get as close to a cold rise when you need it.   

Thanks for all your really intresting posts,   p

[wookey]

Do you mean 1.1KWh per cycle?
(1.1KW is a measure of power, not energy consumption.) Ah yes, a bit of googling shows that consumption varies from 0.8KWh to 1.1KWh for A-rated machines. A hand-washing bowl of 45C water is about 0.35Kwh (8.5l, 35C temp rise on average). You might need two to do the same as a full dishwasher?, so they use between 20% more and 3 times as much, depending on how full it is and how much water you use hand-washing. Of course if that was free solar hot water then they use infinitely more.

I might do some more handwashing now I've worked that out.

[Capcave]

There was some research somewhere (which I can't find at the moment) that showed a family of four is the point at which you are better off in terms of energy and water consumption with an A rated dishwasher than doing it by hand. If you are are using solar this will come down a bit I guess.

[Bob]

you are better off in terms of energy and water consumption with an A rated dishwasher than doing it by hand

Are you sure about that?  I suppose it might depend on how many times you change the water in the sink.

[Bob]

Something I find very annoying is my 16 year old daughter's propensity for purchasing clothes that cannot be washed at home.  They have to be taken to the cleaners.  Either that or they insist, according to the label or her, on being boil washed.

[Capcave]

This was not the one I saw but is the same sort of theme. Basically new dishwashers use less than the average person doing the washing by hand - obviously if you are careful by hand you will be better than the machine.

http://www.landtechnik.uni-bonn.de/ifl_research/ht_1/EEDAL_03_ManualDishwashing.pdf

[odbob]

The efficiency rating of most modern appliances is a laugh, when you consider their unreliability, very short life, sometimes just outside the warranty period, and therefore the true amount of embodied energy. This goes for so called highly efficient condensing boilers too.
That said, I'm happy to use these modern appliances, and do tend to look at the energy requirements before purchase

[Capcave]

I did buy a "brand name" dishwasher from a well know high street store some years ago and it did do as exactly as you said - packed up after 12 months etc etc. I then bough a Miele at an extortionate price but it has now done 8 years used every day without a single problem (due to the manufacturer). I even mistakenly fed three phase into it (wiring error down the line) and only had to replace one resistor. I've plumbed into a hot feed which also cuts the heater time required by a lot.

[wookey]

Capcave - that's a fascinating link. I am boggled at the person who managed to use over 450l of water to wash 12 settings of washing-up!

Also interesting that they reckon dishwashers are noticeably better than (average) people in terms of getting things clean on average. I know ours isn't - it's pretty cr*ppy on that score (and we use a fair amount of water pre-washing things to give it a fighting chance). No mention of that in the test, but then it takes us about 4 days to collect a machine-full so the stuff gets a lot more than 2 hrs to dry on, which is what that test used.

Still, clearly my hand-washing energy/water consumption estimates are the 'very frugal' end of the spectrum.