All,
Apologies for further dragging this thread out even more but you might be interested in a spot of ping-pong email I had with ISE Appliances. It reminds me of the Monty Python sketch "did you pay for the 5 minute argument or do you want the full half hour?".
Read on:
Dear Sirs,
Does your washing machine accept Solar Hot water?
This is the future (within the life of your machine!) - I have a solar panel that heats hot water for free. So ideally a washing machine would:
Divert the hot fill via a special outlet to a rainwater collection or drain...to purge the pipe of cold water.
When hot enough it would fill the machine with hot water, adding cold only if necessary.
After that NO electric should be used to heat water. Repeat NO heating!
There is an industry trend to cold fill only. This is WRONG environmentally; not only do we need hot fill restored we need advanced hot fill to perform like my suggestion. With a solar panel hot water is free so electric heating should be eliminated, perhaps with a simple switch.
On the Navitron renewable energy forum the topic of eco-friendly washing machines is often discussed, but none of the pioneers are happy with the Industry status quo. At the moment "eco-friendly washing machine" is an oxymoron and many pioneering environmentalists like the old machines with no fancy computer and simple switches for heating/no heating.
See:
http://www.navitron.org.uk/forum/index.php/topic,6352.0.htmlI would be glad to discuss these technical ideas further
best regards
Paul
Hi Paul,
There are, currently, no machines on the market that fill intelligently in the way that would allow this to work in such a way as to save you money or heating water in the machine itself I'm afraid. In fact it is rare these days to see one that has hot fill as, due to the low fill levels on modern A Class washers the amount of water drawn is usually not enough to draw any hot water from the system. Any machines with a hot fill capability will generally only fill with hot for one fill on a 90˚C or higher wash after the pre-wash stage and at no other time.
In effect, the actual amount of warm water used will be very dependent on the length and bore of the pipework to the machine which will determine how much water is lying cold in the pipe itself.
Therefore, while in theory drawing from your heated water saves energy in practice it very much depends on the length of the pipe from your heat source to your tap or the time till hot from a combi or condenser boiler. In the vast majority of homes the pipe run is too far or heat time is too long (often both) and the customer ends to paying a premium for a hot and cold fill machine which is actually operating as cold fill. All it effectively does is fill your pipes with hot water which goes to waste. Because of this we do not supply hot and cold fill as one offs to individual members of the public as it is highly unlikely that it will save them any money in the vast majority of cases.
To demonstrate this take a 1.5 litre empty plastic bottle and fill it from your hot tap. In the vast majority of cases the water will be at best luke warm and in the vast majority of cases it will be stone cold and need to be heated to wash temperature in any event.
To get hot water to the tap means running off the cold water lying in the pipework and effectively wasting that water, to fill intelligently would require that you waste the same water for every instance where the hot fill is called for. Of course in areas where water use is metered this is costly as well as impractical.
Asides from which there are a host of other problems with hot fill, not least of which being that you cannot control the incoming temperature which can cause damage as well as cause detergents not to work as they should since they are designed to operate on a temperature curve, not immediate immersion in hot water.
I hope that helps but if you need any more information please feel free to ask.
Kenneth Watt
ISE Appliances Limited
Kenneth,
Thank you for your reply. I fully understand all the issues you raise.
But the eco-warriors purge the pipes of cold water before starting the machine. Some of them even have pumps to recirculate water back into the header tank until the feed is hot! The latter will not waste any water at all.....alternatively my suggestion of a grey water outlet into a rainwater collection tank allows that water to be used later for flushing toilets, eliminating the waste.
Also many solar installations have thermostatic mixer valves (TMV) set at about 50C to safely limit the hot water at the taps, and many have suggested a TMV set to 30C which when purged would fill the machine at exactly the correct temperature for low temperature detergents.
The current situation is ok for now, but I remind you the Climate Change Act requires 80% emission reduction by 2050 and washing machines, powder and their installations will have to become smarter.
All the features I have suggested will have to be implemented, unless of course the householder can generate renewable electricity on site.
regards
Paul
Hi Paul,
The problem is really very simple, there are not enough homes out there that can take advantage of such a machine and, until there is a good volume that can use such a system the factories will not make machines to take advantage of them as they would only work with such a system. There is, much as is the case with home automation systems, absolutely no clarity on the system protocols used or standardisation of installation and it is therefore not possible to produce thousands of machines to meet a single specification.
Yes, it could be done as nothing is impossible, but at a huge cost due to the low volumes. So large I suspect that nobody would buy a machine capable of this as the cost would be extremely prohibitive, leading to even lower volumes.
We have looked at a system that would syphon off to greywater but it's still on the drawing board and it is incredibly difficult to get funding or indeed interest in such a system as almost anyone operating in the field will tell you.
Regards
Kenneth Watt
Kenneth,
What the environmentalists would settle for is a simple machine. Our old Hotpoint had an Eco button that turned off the heating element and accepted hot water at whatever temperature. That would suit many people perfectly and I'm sure it could be programmed into the software.
Hi Paul,
Can't do that I'm afraid.
The machine cannot be allowed to damage clothes and, I'm afraid, that many users will simply not pay enough attention or care to the instructions. So, we have to default to having it so that the incoming water temperature cannot exceed 30˚C wherever possible or it can ruin delicate and woolen fibres.
Asides from which it still doesn't solve the problem that detergents are designed to work on a temperature curve, not instant immersion in hot water. This leads to poor performance/wash results which means that people re-wash the items, this is proven, and just adds to the environmental problem.
Both of which would also open any manufacturer that did it up to claims for damage caused.
I'm afraid there's an awful lot more to it than the simple fact that it can be done.
Regards
Kenneth Watt
ISE Appliances Limited
Has the world gone mad?
-Paul
