Re: For how long do you keep you machine switched
Yeh, Id be interested in some insulation but purely from an efficiency point of view (yes, another engineer like Mark). However, my main gripe about leaving the VBM on, is the sound of the pressurestat clicking on and off. Full marks for an industrial quality pressurestat but couldnt they have found a quieter one? Has anyone looked into muffling the thing? Perhaps some insulation around it as well might be the go.
Bob
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Re: For how long do you keep you machine switched
I know that there have been various threads over the past few years on Coffeesnobs discussing the virtue of insulating boilers and I remember that Mal was instrumental in sending e-mails, co-ordinating a bulk order of insulating material etc. but from memory the order didnt go through.
Is it worth another try now? We have so many more members now...
What do you think?
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Re: For how long do you keep you machine switched
Yep, as Mal said, insulating the boiler also helps....
Also using my 17L monster as an example.... when I checked it over a year ago...... going from memory!
It took about 16-20 minutes from stone cold until the pressurestat first clicked off... but within a very short time it was back on again (as heat was transferred to other components like the groups etc.... so it then cycled at 90% on and 10% off..... and over the remaining time..... up to stability at about 1 Hr.... the duty cycle slowly changed from 90/10 to 10/90...... basically it doesnt draw its steady state 10% until about an hour after switch on..... so to say that 16 minutes at 100% and then 10% would be very incorrect...... It probably averages say 50% (or possibly more) for the first hour..... and then a steady 10% after that......
The time taken to heat up, the power used and the comparison between steady state and heat up consumption will vary from machine to machine..... how well insulated the boiler is..... how large the boiler is..... how many watts per litre your boiler heater is..... and probably a heap of other factors.....
I know when I did the sums on mine..... three times a day from stone cold and then left on for about an hour after heat up (making a few coffees :
) used only a bit more power than leaving it on 24/7...... but I would think smaller boilers may save power if switched off between uses.... just as long as you are willing to wait for it to thermally stabilise each time.
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Re: For how long do you keep you machine switched
If you insulate the boiler, the numbers are much more in favour of leaving it on. The start-up is reduced too though,
Mal.
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Re: For how long do you keep you machine switched
Great research, well done.
Now lets put some dollar values to the energy and we will have the full pictuire.
Must do these tests myself too.
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Re: For how long do you keep you machine switched
Did some timing this evening with the machine - a VBM Domobar Super - started from cold.Originally posted by ml27 link=1216853079/20#28 date=1219892513re: the power consumption, I measured the duty cycle (on time vs off time, for those who arent sure) of the VBM last night once it was up to temp.
Switched on for 15s, then switched off again until 2m35s, then switched on for 15s, and so on.
So its on a 15s/155s = close enough to 10% duty cycle. This would suggest to me that its 1800w element is on 10% of the time when up to temp, or the same as drawing 180w continuously.
Will do some more measuring of on/off times while the machines warming up..
Mark
To cut a long set of numbers short, the machine reached equilibrium (fully warmed up) after about 58 minutes. The element was on for a total of 13 minutes 48 seconds during this time.
At a 10% duty cycle when operating in equilibrium, the machine would take 2 hours 18 minutes to use the same amount of energy.
To use the same amount of energy as leaving the machine on 24/7, one would have to go through over ten startup cycles (lasting one hour each) every day.
So the moral of the story appears to be that from an energy standpoint, its worth turning your machine off when its not in use. Other considerations, such as being able to have a coffee on demand, will probably outweigh this
Mark
ps. can you tell Im an engineer? :
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Re: For how long do you keep you machine switched
I thought that the dual purpose single boiler machines have some sort of overheat protection switch that cuts the boiler element so that the element doesnt burn out? It happened to my silvia only recently that I had all the switches on at once on a pretimer (thanks to the reverse order of italina switches) and by the time I got to it the silvia was "dead". Sent it to Mocopan and it got fixed. I expected the fix to be a new boiler and a new pump but it turned out all that was required was a reset of the overheat protection switch...
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Re: For how long do you keep you machine switched
Gday ALC,Originally posted by A.L.C. link=1216853079/20#32 date=1219966328Another question Chris,
how can you tell when the boiler is completely full on a VBM Domobar Leveta?
If you run water through the steam wand, it has to be full
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Re: For how long do you keep you machine switched
Another question Chris,
how can you tell when the boiler is completely full on a VBM Domobar Leveta?
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Re: For how long do you keep you machine switched
Its possible to kill an element in a dual purpose boiler due to the fact they dont auto fill. I have had 2 x dead VBM Levetta this week...Originally posted by A.L.C. link=1216853079/20#30 date=1219964865Hi guys,
I have a few queries, although they possibly relate more to the sub-$1500 machines ...
Are there any problems with leaving a single boiler (eg. VBM/Silvia) on all day? Does it use more power than an HX? Because the boiler doesnt auto fill might the element get damaged?
My advice is ensure the boiler is completely full immediately after you texture milk. I run water through the group and then out of the steam wand as well- to protect the element.
A new element is under $50- but the boiler must be removed to fit it, so you get slugged an hour of labour for a Levetta. No Silvia boiler replacement will be under about $250 and even a repair will set you back around $150. Worth taking the risk :-?...I dont think so...
Chris
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Re: For how long do you keep you machine switched
Hi guys,
I have a few queries, although they possibly relate more to the sub-$1500 machines ...
Are there any problems with leaving a single boiler (eg. VBM/Silvia) on all day? Does it use more power than an HX? Because the boiler doesnt auto fill might the element get damaged?
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Re: For how long do you keep you machine switched
some more than others TGOriginally posted by Thundergod link=1216853079/20#27 date=1219884676Dont we all?
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Re: For how long do you keep you machine switched
re: the power consumption, I measured the duty cycle (on time vs off time, for those who arent sure) of the VBM last night once it was up to temp.
Switched on for 15s, then switched off again until 2m35s, then switched on for 15s, and so on.
So its on a 15s/155s = close enough to 10% duty cycle. This would suggest to me that its 1800w element is on 10% of the time when up to temp, or the same as drawing 180w continuously.
Will do some more measuring of on/off times while the machines warming up..
Mark
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Re: For how long do you keep you machine switched
Dont we all?
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Re: For how long do you keep you machine switched
and given his "OCDness", does he have a super consistent (almost ritualistic) dosing and distribution technique?
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