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Re: Really smart tumble dryers?
Had a reply from Crosslee.
First off my impression is they thought that heap-pump dryers were the focus (why does everyone still think these have a future?) But the stumbling blocks were damp airborne lint and longevity. (As if they care)When pressed on the simpler heatcontrol idea, It was such an old and obvious idea ( of course) but how could any humidity sensor avoid the damp airborne lint. Even a simple thermocouple on the heatexchanger would be an improvment, but clearly while theres an excuse why bother basically.
Like I said they dont give a toss and are happy to sell simple crap to simple people.
Looks like I’ll have to play with my own. What a shame though.Re: Really smart tumble dryers?
How can a couple of sensors use as much or more as would be saved.
Your talking a couple of milliwatts of power for a few sensors???I wasnt sure how to take your post at first, but I’ll give you the bennefit of doubt. You really must look up dew point and try and understand what relative humidity means. (without meaning to sound arrogant)
I do agree with the washing line bit wholeheartedly. (Even with all the ironing) but you tell all the retailers, customers, Govt and even builders, and everyone that wants to speed up drying times, reduce costs, save energy and keep the kitchen at a reasonable temp.
But to be clever washing wont dry in the rain or when outside air temps low and RH are high. (Assuming atmospheric pressure remains the same)
All ready been down the heatpump road. Not going to happen. Prices even if hp becomes workable are still ridiculous.Regulating heat, optimizing conditions in dryer seem the best / simplest /cheapest / practical answer. Cant believe its not on the shelves.
Or taking your suggestion I could ask the missus to blow on it.
There’s a thought!Re: Really smart tumble dryers?
Yeah thats what I guessed. Full on heat untill resistance drops.
That system or something like it, would still be needed to measure how dry washing is, and especially as RH sensors were never that good at low levels. So really any system that ‘controls’ the heat can only be good. Most likely save a fortune.I’ll email crosslee and see what they have to say.
Re: Really smart tumble dryers?
Of course they would probably cost ‘a bit’ more, but that shouldnt be the criteria to stop in progress or better design if its possible. It wouldnt be very hard to do or implement either if people just damanded better than the crap they are happy to fork out a couple of hundred quid for for so long.
Big builders like Crest Bovis, Barret etc dont need to pass building reg. The NHBC pass everything they build and tell buyers to make a claim if buildings not right. Also worth noting is that many of the tousands of new homes built and and planned are under control of the Housing corp Social housing (new Govt private empire) and whos going to enforce regs for them? The government?
But this is not why I asked the question. I’m happy to play and modify my own machine if need be. I just wanted to hear if its been done.
Re: Really smart tumble dryers?
Yes it does look nice but dependent on the setting selected still. It doesnt appear to control heat power, just time (low bake or fast bake).
Given the high temps and the crappy small heat exchangers manufactures use, they get so hot its a wonder that any water vapour condenses. Especially in my sauna like kitchen, especially without taking into account the rise in ambient air temp.
I thought perhaps Bosh or Miele might have one perhaps. Think of all that heat energy wasted. The Gov keeps moaning about global warming like its ‘our fault’ forcing millions of homes (flats) to be built without washing lines, and rely on manufacturers to save them power. SadRe: A little moan about trade sales
Got her one now (Currys) and I’ve calmed down abit.
Bloody shame though that even the links you gave, nearest is nearly an hour away (Chichester) by car.The links were very thoughtful though, thank you.
Re: Yet another Samsung side by side problem
Yea I was, thanks for the info. Its just nice to get your head around and understand some of these problems. I couldnt work out why you had high temps while on defrost, but you’ve answered that.
Glad you’ve got it sorted.
Re: Yet another Samsung side by side problem
Mate, just noticed this thread. Your probably happy with this now but wondered while your checking it out your certain the fan turns off while on defrost.
Re: topic enquiry
Totaly agree with all you said mate, and do have the very same sentiments about customers and (domestics).
They do gawk at every thing that costs them a quid. While they’ve seen there money pits not only allow them to live in comfort without cost, but actually return a large profit at the end as well, with little more than a few coats of Magnolia and twigs. (Hope we’re on the same wave length) So installing a decent bit of kit that will enhance their comfort, AND increase the home value even more, which realy is no different to a reasonable av setup in cost youd think theyd realise by now.That said, the same could be said for any cheapo appliance, like a washer or dryer that costs even less and we all still have a go at fixing them, even with some as crap as they are. I have.
I’ve in the past installed many many commercial splits and industrial ac with some that are excellent and many that arnt. But very few could you ever stick in your house, or want to.Its only in recent years that technology has allowed the manufacture of ac at affordable prices and of a size people want, and my feeling is that will improve. My preference would be Daikin every time but equally I’ve known very small Mitzi’s so quite and reliable you just wouldnt know they were there, and I’d be happy to have one in my bedroom.
But with a b&q cheapy ac upto 17000 (about 5KW cooling) for a little over four hundred quid, even if chinease or arab made, that aint bad. Ok might not last much longer than a cheap dishwasher but thats the way things have gone.
And sadly I think the designs are now such that the science and art of refrigeration will continue to fade away so the average plumber or sparky is quite competant enough to fit or ‘regas’.But that wont stop me having a go.
Re: heat pump tumble dryer
Well it was just a thought. Wouldnt be wasting anymore than already. It only sits in the tank waiting to bve used anyway. I want the washing to come out warmer so it ‘should’ reduce heating needed straight away / increase water condensing rate .
Anyway just found a couple of links might be interesting.
The bottom one is more of the sort of heatpumpdryer that I remember:-
Re: heat pump tumble dryer
I agree with some good points. Peltier on the heat exchanger I hadnt thought of and they’re starting to be more popular now with fridges too. A good market might be retrofitting existing condenser packs. Only needs to be colder than the dew point and be big enough for the load so an easy ‘upgrade’. Very power hungry, but very usful in hot humid areas.
Another thought, something I might try is swapping hoses temporarily on the washer to use hot water instead of cold. After thinking about this its obvious that ‘hot’ washing that goes into the dryer will give it a head start. Its a shame you cant prog the washer to give a final rinse in warm or hot water. I’ve a big water tank on the go all the time that only gets used to wash a few cups. Shower mostly, so might as well try it. Should increase drying time.
But got to say I feel its legislation that ‘controls’ or stifels innovation and competition.
Certainly manufacturers could do a lot better than they do but only do the minimum to stay in front of legislation knowing thats all their rivals will do.Re: heat pump tumble dryer
Hi Guys, still strugleing? It is difficult to get your head around. The whole heatpump drying business blew me away and that was after years already working in refrigeration and college.
Something to bear in mind when comparing ac and heatpump dryers is they ARE the same refrigeration process. The transfer of thermall energy from one side to the other. That said, when you then make comparisons about temperatures close to .. or nearly … the applications are a world apart.For a start on a basic or even highly complicated and complex ac system the whole point is that there is an ever increasing temperature difference between the cold (evaporator) side and the hot (condenser) side of a system. The cold side suction gas cools the compressor. Also there is a temperature difference between ambient (outside) air temperature and the condenser coil. Lots of oppertunity to get rid of that excess heat.
In a heatpump dryer its both coils need to be on the inside. The excess heat from the condenser is used to continue heating the load. Not only that, you are still ADDING heat to the same load to evaporate the water but also from the system itself. Think of a de-humidifier in a steam room, with extra heaters and a couple of fans blowing at it. But remember if the load that your drying gets to say 50’c, your evaporator is at the same temperature. And its from all the thermal energy of the water vapour, (from the energy of condensing water vapour) of the water condensing ( that makes the whole thing so efficient) but your suction gas is going to be pretty high at 50’c and so the refrigerant is at quite a high pressure already. There are many things that can be done to help, such as additional outside coils, but it is by its nature a cruel process.
I think its completly possible without doubt to scale the whole thing down to work and fit inside a large dryer, but parts would have to be first rate. Especially with the pressures, but I think its likely that the process would be adapted to not work quite like (and so with out all the bennefit) of a large commercial heatpump (dehumidifier). My feeling is that if one does appear it will more likly appear much like a normal ‘condenser’ dryer you get now, but with only an assisted cold side on the heat exchanger. Theres even the possibility of cycling cold water through a water cooled heat exchanger to below the dew point.
Hope this helps
Re: heat pump tumble dryer
Mate your not asking much. Not only are you asking to explain theory of refrigeration and knowledge but stuff you might never read from a book. Please read up on thermodynamics. (Heat)
But to explain briefly in ‘heatpump’ tumble dryer terms.
Think about the washing you would like to dry. How much does it way? Its this weight or mass you need to heat up – not air as an ac unit.
You need to heat the washing so the water evaporates (not all of it at once) but enough to get process started. Once water has turned to a vapour (wet air) it has gained some energy (heat). This then is atracted (for want of a simpler description) to anything colder (because it wants to turn back to a liquid, while at the same atmospheric pressure)
When it lands on the ‘colder’ evaporator coil it turns back to a liquid but in doing so gives up its energy (heat). This heat aids the adiabetic epansion of the refrigerant to also evaporate, the same way an ac system works. However a lot more heat (but QUANTITY not just TEMP) Imagine using your hair dryer even on a hot setting to dry your washing, it wouldnt be big enough right. Thats because of the qty of heat measured in jouls,watts, btu and so on. But this heat gets passed around the system and is got rid of from an already hot condenser coil, and is then used to continue heating up the washing even more. More heat – more water and so on.
Problems are caused not only by controling the whole process but by the mechanical damage. Much higher temps and pressure than any ac will ever deal with, and like your car look after it and it will last longer. Thrash or modify it to work on a race track and it will have more faults and wear out quicker.
Remember this. Only the theory and principles of refrigeration are the same. The application is completly different.Hope
This is hHowever,
Re: dryer choice?
right back to this thread..
If anyones bored and reading this might be worth noting the outcome.
Didnt go for the Zanussi as suggested, nice idea and greatful for suggestion but in the end I bought my old ladys dryer cheap to make do. She was getting a new one also. But it has meant taking off the drawer /door front and plinth board to make room for this monstrous thing. (Aquarius tdc 30) (total diabolical crap).I had really wanted a smaller compact dryer condenser type, that I could fit in a box base unit as it were, basically the hole left from a 600 kitchen base unit, and close the front door making the whole thing look as if it was a normal cupboard / drawer cupboard. (Yes like an intergrated)
Sadly the reason I didnt go for the zanussi was that all buttons were low down and these and the door would have fould the plinth board.
Geez what a bloody nightmare. The simplest thing, and these usless manufacturers cant even grasp the concept that perhaps people DONT want to see a bloody great ‘nearly empty’ box in the middle of the row of nice kitchen cupboards sticking out six inches. And we dont all need a dryer with a drum the size of a gassometer?And honestly, after cleaning and then attempting repair on my old ladys dryer if I made and sold boxes the way HOTPOINT do, and probably like many others nowadays I would want them hidden away out of site to avoid the embarrassment. But its all about ‘branding now, not quality or engineering. I must say I was shocked. I’ve not ever seen a hair-like heating coil element made from a workshop shaving, wound round a wafer thin piece of mica board. Imagine people doing aprentiships?? to learn how to do that.
And this is connected TO THE MAINS???
These marketing people ‘those who have no brains’ might just as well sell a BIG white inflateable box with a few led’s, add a hotpoint logo, and include a ball of string to hang the washing on. But I guess even that would eventually end up a thread made from cornflour. (In the pretence of keeping costs down) Still as long as they have nice well paid jobs, sod the rest of us idiots.
Cant wait for the chinese industrial revolution.
