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dishwashers and solar hot water

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Started 11 years ago by sandystone
Latest reply from swanning_it

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sandystone
Member

Our dishwasher uses about a unit (1 KwH) per load, and much of that energy is to heat the water. This is roughly 1/5 daily household energy usage.

We selected about 2 yrs ago on the basis of energy and water efficiency, and quality and quietness, yet the inlet was 'cold water only'. This is the only aspect that has bothered me.
Recently I rang and wrote to Bosch (just to get 2 separate opinions)and discussed what they meant exactly by 'cold water only'.

They said the water temperature can not exceed 60 degrees.
They said that the drying cycle wont work well though. (Is cold water circulated in the internal casing to condense the hot water and steam to do this?)
The dishes dry on the shelves anyhow as we generally unload when things are still hot.

As normally is the situation our hot water goes through a limiting valve, coming through at 50 degrees I reason that there should not be a problem connecting to our hot water system.

On this basis I am likely to connect our machine to a hot water inlet.
Has anyone else tried this? Any dramas?

Posted Saturday 12 Feb 2011 @ 10:16:20 pm from IP #
Sunshine
Member

sandystone,
I have a solar hot water system where I have had the dishwasher hooked up to the hot water connection for over 2 years.
I have a Dishlex model, which supports hot water connection, but as long as your SHWS has a tempering valve (now required by law in Qld on new installations), which reduces the temperature to 50 degrees, that should be fine on your Bosch.
I have an LCD real time power monitoring device, and have found that the dishwasher doesn't need to heat the water at all, and only briefly uses the heating element to dry the dishes at the end of the cycle.
Dishes dry fine.
Definately a big power saver running your dishwasher off solar hot water.

Posted Saturday 12 Feb 2011 @ 11:26:23 pm from IP #
hamish05
Member

I explored the possibility of converting my Electrolux Dishwasher to SHW with their AU Customer Care recently. The following is their reply to my email enquiry.

I am able to advise that it is not preferred that you connect this dishwasher to solar hot water, however it is possible to do so. For best wash results and for the benefit of your dishwasher, it is best used connected to a cold water connection. If you choose to connect to solar hot water, the system must have a tempering valve or function installed to limit it to 50 degrees Celsius.

During the beginning of your dishwasher cycle, it will fill with approximately 4-5 litres of water. This water will be the water that is currently in the pipes (usually cold water) and will not necessarily be hot, depending on how far the hot water service is from your appliance.

The dishwasher will still heat the water as per normal, depending on the program you are using, and you may save a small amount of energy in that it may not have to use it's normal energy output to heat the water quite as much.

It may be helpful for you to know that this dishwasher's energy consumption is only 233 kWh/365 uses. The Australian Government advises that this usage only costs $396 over 10 years of use, assuming that the dishwasher is used 7 times a week. You may wish to visit the Australian Government's Energy Rating Website, http://www.energyrating.gov.au, to use their calculators to obtain more usage figures. As the DX403SB is no longer a current model, you can use the model number DX303SK for these calculations, as this appliance has the same energy rating of 233 kWh/365 uses as your dishwasher.

Please do not hesitate to contact us if we can be of further assistance.

Kind Regards,

Nicci
Electrolux Customer Care
1300 363640

Don't take any notice of the energy consumption quoted above, as that is measured on the ECO Cycle, which I suspect few people use as it doesn't do a very good job. My measurement of the Sensor Cycle is just over double the consumption quoted.

A Technical person from Electrolux told me that most dishwashers are connected to cold water because some research had shown that different foodstuffs etc on plates dissolve at different temperatures (as the cold water heats up). He in fact had his own dishwasher connected to his SHW and was extremely satisfied with the washing results.

I am in the process of converting mine to SHW, it's unfortunately not easily done in my case.

Posted Sunday 13 Feb 2011 @ 1:15:42 am from IP #
Buzzman
Member

Having a "cold only" inlet means the dishwasher maufacturers do not have to install an expensive tempering valve, nor do they need to fit both hot and cold inlets, which further reduces cost of production.

Of COURSE it's done for OUR benefit!!!!!

Sunshine
As admirable as your efforts are, connecting the SHWS to the cold inlet and thus reducing the enregy used to heat the water, perhaps you could consider switching the machine OFF as it reaches that part of the cycle which incorporates the electric drying.

You may need to watch it like a hawk for one full cycle so as to measure the time it takes to reach this point (your power meter will show when it switches on) but ever after you will merely need to set a kitchen or oven timer to that "cycle elapsed time" and when the timer alarm rings, switch off the dishwasher.

Then open the cabinet and roll the drawers out and let the dishes air dry, just as you would if you washed them and set them in the drainer on the sink.

Thereby also saving the power that woudl otherwise be used to dry the dishes.

ALL:
Dishwashers are a scam, perpetrated on a gullible public. Not only do they use power to wash, rinse and dry dishes, people who regularly use one report that ther is usually some item that cannot fit into, or is the wrong kind of material to go in the dishwasher.

These items have to be washed in the sink. So the sink has to be filled with water anyway. In this case, how id the water used by the dishwasher SAVING water???

Surely it is using MORE water than the sink alone?????

Another argument I use in attempting to convince people of the lack of "need" for the dishwasher is this:

"Would you go next door and ask your neighbour to come and wash and dry your dishes for you, offering to pay them to do so?" You would never do that, would you? (Everyone says 'no' BTW).
"So, why are asking the power company to do it for you then?"

Food for thought.

Posted Sunday 13 Feb 2011 @ 1:34:55 am from IP #
hamish05
Member

That is an unbelievable viewpoint. Why not just completely do away with the need for dishes all together?

Anyway, I produce the energy you infer I am wasting.

Posted Sunday 13 Feb 2011 @ 2:03:12 am from IP #
Jeffbloggs
Member

Buzzman
You wouldn't get very far with that argument with my wife. She would simply request that I find/design a device that can do it! She hates dishes. You could have self cleaning dishes etc, or a steam powered cleaning system. You could even produce steam using solar evac-tubes, and wouldn't need detergent for cleaning. The same system could be used for cleaning laundry...imagine a cupboard in which you simply place your garments on a hanger, and then simply remove after 5min perfectly ironed. Otherwise some ultrasonic disruption could be used, like is done for lab equipment. Microcavitation can produce micro bubbles of up to 1000'c and 100bar pressure, which disintegrates all organic matter in seconds, but without damaging fabrics/porcelain if tuned correctly.

Posted Sunday 13 Feb 2011 @ 2:04:29 am from IP #
rockabye
Member

Withdrawn. Off topic.

Posted Sunday 13 Feb 2011 @ 2:28:47 am from IP #
Buzzman
Member

hamish05
Unbeleivable? Sorry, very believable. We need, in fact we MUST reduce our consumption of energy in EVERY way possible.

Dishwashers are a so-called 'convenience' item that I have demonstrated is a complete scam. And uses power unecessarily when simple hand-washing is simpler, quicker, cheaper, and uses less water and less energy. QED.

As rockabye says, only for the lazy.

JB
Perfect opportunity to save energy and earn brownie points. Why don't YOU volunteer to do the washing up? No more arguments, n'est-ce pas?

One theory I have come to about the con job of the dishwasher is that, in our hectic, busy, time-pressured Western culture (note the emphasis) the myth of 'time saving' is easier to believe, and especially when storing the dirty dishes in the bacteria-filled, festering steel cupboard all day makes them simply 'go away'.

Another point of view is that it enables busy people to pretend to themselves that their kitchen is pristine and clean, simply by removing the dishes from the bench tops.

This view comes back to our well-known human failing of seeking and imposing 'order' on our environment.

The myth of the perpetual need for cleanliness and destruction of ALL bacteria and micro-organisms has lately been proven to be, in some cases at least, detrimental to human survival.

It is now accepted that the rise in 'anti-bacterial resistant' bugs in hospitals is largely down to over-cleaning and over sterilising, forcing the survivors to mutate and evolve more rapidly than they otherwise would have done.

Joseph Lister and Florence Nightingale have a lot to answer for.

Although these days I'd say it's Provtor and Gamble and UNilever who are the biggest peddlers of such 'cleanliness' myths.

Posted Sunday 13 Feb 2011 @ 4:53:05 am from IP #
Bullwitter
Member

I NEED a dishwasher. The kids refuse to wash anything without one. PS. I have had it connected to the hot (solar) tap only – for years with no problems.

Posted Sunday 13 Feb 2011 @ 5:12:56 am from IP #
rockabye
Member

Withdrawn. Off topic.

Posted Sunday 13 Feb 2011 @ 5:19:23 am from IP #
Bullwitter
Member

But they are convinced their world IS the real one!

Posted Sunday 13 Feb 2011 @ 7:20:31 am from IP #
hamish05
Member

It is indeed a shame when somebody asks a reasonable technical question, and instead of help being forthcoming, certain members take it upon them selves to belittle the subject and lecture about their standard of lifestyle.

I for one DON'T need your opinion on how I should conduct my personal affairs/life, or how lazy you deem me to be.

It's a real pity that a moderator doesn't step in here, as this standard of response will ruin this Forum.

Posted Sunday 13 Feb 2011 @ 8:37:22 am from IP #
rockabye
Member

I don't own a dishwasher and the previous posts were off topic and have been withdrawn. Bit like parliament I guess. Thus I have self moderated. Good luck with your query.

Posted Sunday 13 Feb 2011 @ 8:49:59 am from IP #
swanning_it
Member

This thread reminds me of the Blackadder skit about the turnip shapped like a certain bit of the male anatomy and his ludicrous puritan Aunt and Uncle Whiteadder!

http://www.youtube.com/watch?feature=player_detailpage&v=w3ew8oj-A8I

At least they realised they're comedians

Posted Sunday 13 Feb 2011 @ 8:59:05 am from IP #
sandystone
Member

Thanks for all the responses, esp to Bullwitter who has done exactly what I intend.
As far as I an concerned the dishwasher saves an enormous amount of time. The kids unload.

It is hard to maintain the extreme position in every aspect of life- I imagine all on this forum are very interested in honing down their energy consumption.

I will start a new topic.....

Posted Sunday 13 Feb 2011 @ 9:08:05 am from IP #
swanning_it
Member

sandystone, you list your occupation as an energy assessor. In my mind, we have some assessors who work with their clients to achieve a good result at tempering normal everyday reality with good energy efficient principles and then we have some other assessors who preach and belittle and expect cave dwelling-like existances from their clients. Might suit some, but in the catch words of forums like this, I doubt those extreme demands are economically sustainable.

I washed dishes for years before a dishwasher and we'd use about the same amount of water. If you're semi-retired and only a couple, fine wash the dishes (I'll probably do the same in retirement) but with the busy lives we tend to lead today, the less time in a kitchen the better. I think even the well-to-do caves today have dishwashers.

Posted Sunday 13 Feb 2011 @ 9:33:20 am from IP #
Jeffbloggs
Member

Buzzy-buddy
You stickin your nose into other peoples business again?
On the bacteria front I agree, there is a lack of balance, and add Pasteur on that hit list of anti-bacteriaurologists. The original "terrain" version sounds much more plausible than the bacterial/viral propaganda.

But on the subject of dishes...I used to do this for when my love for her was young...and naive It always seemed to have the "desired" side effect at night when she came home from work....
But now with my extensive full-time duty as resident stirrer here at the ATA forums, I have now other commitments!! lol

But I do agree with "the others" on dishwashing, or any "chores" for that matter. My mother used to find it impossible to do dishes with her arthritis, a dishwasher was a must to ease the suffering. There are simpler ways of keeping things hygienic, I gave a few options that everyone seemed to ignore, but such is life. I'm all for progress in the right direction, not regress towards cavemanship! (nothing being implied here btw)

Even though I believe we should reduce energy consumption of fossils, I do not necessarily think that this is necessary if one uses RE/Biomass etc as a fuel, I think there is a way to increase "quality of life" with intelligent tools and environmental levers. Life can still get a lot better, even if it is to remain sustainable. It's the fossils that are the problem, get rid of those by whatever means, but until then there are bigger fish to fry, before we can wash our hands on the subject of excessive consumption from dishwashers.

Posted Sunday 13 Feb 2011 @ 2:53:56 pm from IP #
Buzzman
Member

I agree, and to those (hamish, swanning) who saw my previous posts as in some way denigrating them or their lifestyle, forgive me for such was not my intent.

I think that connecting a dishwasher to solar hot water is a great start, but I go further and suggest clients do the "switch off the drying cycle" as well.

It costs little in time, saves energy, and gets the same results you would achieve with hand washing, just air-drying the dishes.

I think the "back to the cave" analogy needs to be on another thread, as this is MUCH more to do with consumerism, 'convenience' and resource consumption than simply a discussion about dishwashers.

But for the record, I do not resile from the position I outlined. Dishwashers ARE a scam, they ARE wasteful of energy, water and time, they DON'T get the dishes very clean either, and ownershp of a dishwasher is a luxury only WE in the 'developed West' can afford. But that is another thread again.

Oh, and Bullwhitter, if your kids won't do the dishes without one, let them starve, or move out.
If you give in to THEIR bullying you will never hear the end of it.

If we kids were in the shower longer than 5mins our dad simply turned off the hot water at the main inlet. Cold shower. Get out quick. It doesn't take much discipline for kids to appreciate what is required.

I suspect the real issue re the dishwasher is the assumptions behind the notion of what are 'needs' and what are 'wants'. But that too is another thread.

Posted Monday 14 Feb 2011 @ 4:12:44 am from IP #
Sunshine
Member

The thread is called "dishwashers and solar hot water", not "should we ban dishwashers or "should we wash dishes by hand". That's for another thread for another discussion for another day.
I think my setup using a dishwasher on eco cycle using solar heated hot water uses around 600Wh, so it probably uses less energy than the average Joe Bloggs who washes by hand using electric hot water as a heating source.

Posted Monday 14 Feb 2011 @ 10:51:42 am from IP #
swanning_it
Member

Buzzman wrote "Dishwashers ARE a scam, they ARE wasteful of energy, water and time, they DON'T get the dishes very clean either"

I can only suggest that the dishwashers to which you refer, weren't very good. Our dishwasher is excellent (in my consumerised eyes) and doesn't suffer any of the issues you raise. It's whisper quiet (in fact often I can't even tell if it's on), it uses minimal water and power, it cleans exceptionally well, it is not a germ breeding ground and I honestly can't see how they waste time. Everyone has to stack dirty dishes, put away clean dishes and wipe down the benches and that's all we have to do with our dishwasher, so as for time wasting......??? What I do know, is that it is a God send to us on a daily basis.

Sunshine has outlined his concept, which makes for a great Beta site for this forum.....many assessors could learn some real world, real life, real people data from his home. What I fear the most, is when anyone, be it an assessor or not, turns ecocentric fundamentalist, they risk turning off people entirely, rather than working sensibly with them to effect real change (albeit less than their personal extremist ideals). So for me, the question is moreso, is it not a more productive outcome to effect some change, rather than no change at all?

Posted Tuesday 15 Feb 2011 @ 7:44:32 pm from IP #
hamish05
Member

Sounds good to me swanning_it. Couldn't agree more with your thoughts.

Posted Tuesday 15 Feb 2011 @ 11:26:40 pm from IP #
Lucas
Member

I enjoy hearing all points of view. sometimes the slightly more radical ones are what makes us think deeply about our ingrained habits. sure, there's a responsibility to keep it civil and i don't necessarily agree with everything everyone posts but i like how people can throw these thought provoking ideas up, even when they are a little off topic

Posted Tuesday 15 Feb 2011 @ 11:52:50 pm from IP #
dave lawrence
Member

dogma (as in radical ideas /evangelism ) spelt backwards is AM GOD .
dogma changes nothing.
it alienates people , but then maybe that is the point .. to feel different and superior.

Posted Wednesday 16 Feb 2011 @ 12:25:04 am from IP #
Buzzman
Member

Lucas is right. We all need to challenge our own perceptions of what we 'need' and what is 'right' or 'wrong'.

Like the example in another thread of the fellow who was buying a Hybrid Camry because it had 'more power' than the Prius, but having stated his principle reason was for better economy, which the Prius provided over the Camry. 'Wrong' thinking.

I'm quite content to 'lose' the argument over the dishwasher. I don;t have anything personal bound up in it.

People will argue blue-faced (and even red-faced) that they 'need' a twin-turbo-charged 6.0L V8-powered muscle car to get them to work, when clearly this is a ludicrous statement bordering on imbecility.

If people are getting annoyed about my pointing out their 'wasteful consumerist habits' then perhaps they need to look more closely at their reactions.

Perhaps the anger is misdirected, and derives from the guilt they feel because, deep down, they know that what I'm saying has a grain or to of truth in it?

Think very hard before you light the flamethrower.

Sure, my position is 'different'. So was that of Jesus in Jerusalem 2000 years ago.

Am I making these statments because it makes me feel 'superior'? No.

I make these statements to create controversy. To make people stop and think.

If you are only REACTING rather than THINKING then could I suggest you do some more of the latter.

If we agree to disagree, after you have done so, then I am totally okay with your decision. It's your life, after all.

But we ALL share this world. Therefore we ALL share responsibility for NOT f**cking it up any more than we already have.

Ergo, anything which uses power (main CO2 producer) that has a cost-effective 'manual option' MUST be carefully considered.

As De Bono dictates: think outside the square. How about a dedicated solar panel or two to offset the dishwasher's consumption?

Not hard when you think about it, is it? :)

Posted Wednesday 16 Feb 2011 @ 4:56:35 am from IP #
swanning_it
Member

"How about a dedicated solar panel or two to offset the dishwasher's consumption?"

Ahh now we're seeing what I meant.....realistic alternatives rather than outright abstinence!

BTW, I drive a Smart car, not a V8 (never owned a V8 in fact). And I'm intending to not just generate my entire consumption, but sell some too! Choices that are genuine alternatives, as opposed to "go without ye sinner"!

Posted Wednesday 16 Feb 2011 @ 5:18:07 am from IP #
Buzzman
Member

swanning

Exactly. I totally agree that if you simply confront people they react negatively (never mind the reasons).

I tend to use an approach I call "the least unacceptable compromise".

So if a client of mine is adamant they 'can't live without' their dishwasher (another patently ludicrous statement, but let's not go there) then I ask them if they'd considered using solar-powered hot water, or using the "no drying" option.

I explain about tempering valves, so they can hook up the solar and not upset new machine warranty and so on.

And I do apologise if you thought I intended to imply that you drove a V8.

And, for the record (so you can all have a laugh at my expense) I used to be a motoring journalist. And my 'favourite car' ATM is the Aston Martin DBS V12.

Cannot possibly 'approve' of them on environmental grounds, and would never own one even if I could afford it. Although, I wouldn't say no to a Tesla. But I have recently been impressed with the large sportscar makers attempts to improve fuel economy. It's a start.

I was day-dreaming the other day about getting hold of an older model Bentley T-series or Silver Shadow and converting it to an EV with LiFePO batteries and so on - not because it would be efficient, not because it would supply 'wank factor', but just to prove that it could be done.

And for that matter, an earlier Cadillac or Lincoln or even a LWB Merc would do - the reason I selected these is the enormous underbonnet and boot space would enable a huge battery bank. Sure, it would need it, but for an "EV Stunt" it would be too cute.

Also, it would be possible to get an older Shadow with a non-running engine for less than $10K, with a potential build cost of less than $40K, ie: less than a Prius, and with better range in EV mode.

This shows what can be done with a more practical 'slider' like a Charade:
http://www.rowetel.com/blog/?page_id=17

The AEVA rocks IMHO.

Posted Wednesday 16 Feb 2011 @ 6:12:04 am from IP #
swanning_it
Member

"And my 'favourite car' ATM is the Aston Martin DBS V12."

My name is Buzzman, James Buzzman........

Posted Wednesday 16 Feb 2011 @ 8:05:33 am from IP #
Buzzman
Member

LOL!!!

That's rather good!!

Posted Thursday 17 Feb 2011 @ 1:37:28 am from IP #
Johnnojack
Member

We have an Electrolux Dishlex machine and it is connected to the hot water (solar) what's more it is untempered hot water and sometimes reaches 80deg After 5 years the dishwasher is still working perfectly. 98% of the time we use the eco cycle. Rain water helps the cleaning standard (no rinse aid required)

Posted Wednesday 2 Mar 2011 @ 10:33:08 am from IP #
hamish05
Member

I have finally converted my dishwasher to SHW, total cost $13.25 and a sore back.

I will quantify the savings here shortly. However the Sensor Wash Cycle took 15 mins less to complete. Presume that is heating time saved.

Posted Wednesday 2 Mar 2011 @ 10:55:00 am from IP #

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