Leaving a Prosumer HX Espresso Machine On DOES NOT SAVE ENERGY - Page 4

by HB on Thu Feb 04, 2010 12:18 am

another_jim wrote:The OP started this thread with an impossible contention that his machine does not obey the first law of thermodynamics...

Ben Z. wrote:Jim, I think Ian is just messing with us.

Indeed, but it's not the first time I've heard the same claim, including from several espresso equipment vendors. So rather than argue physics, I measured using a Kill-a-Watt.

by **shadowfax** on Thu Feb 04, 2010 1:08 am

shadowfax wrote:I don't see what these graphs bring to the table that wasn't already obvious.

I have to say I think I've missed the elephant in the room on this one, and I feel pretty embarrassed about that. Ian, could you describe the details of how you collected your data? Is this a log of a continuous experiment, or a graph extrapolated from some other data/calculations?

In your first graph of your original post, as near as I can tell you display your boiler losing virtually 100% of its heat in 2 hours:

In fact, "virtually" is a generous assessment:

I copied the initial heatup curve and set it next to the subsequent ones; they look pixel-for-pixel identical to me.

But here you show the curve for heat loss in an insulated boiler taking 9 hours:

So, does your uninsulated boiler really cool off to room temperature in 2 hours? That strikes me as hard to believe, but you drew your curves that way, and so it makes me wonder if your measured data is 100% contiguous; it looks to me like it may be experimental data extrapolated in an inaccurate fashion, i.e. with the assumption that the boiler cools 100% in 2 hours.

by **cafeIKE** on Thu Feb 04, 2010 10:53 am

Mea culpa. :oops:

The first graph is a composite of a heat and a cool data sets and I've made the most idiot blunder.
The cool down logged at 10 minutes, not 2:30 interval.
There was no intent to deceive.

My most sincere apologies to the group for wasting their time. :oops:

by **another_jim** on Thu Feb 04, 2010 11:47 am

My apologies for going ballistic; I thought it was some sort of provocation. But a web search turns up lots of people have made the same mistake about short turn offs not saving energy; not just for espresso machines and hot water heaters, but even for light bulbs.

by **shadowfax** on Thu Feb 04, 2010 11:52 am

Along the lines of what Jim mentioned above (about this apparently common myth), Chris Tacy sent me this last night, a similar application of what's at play applied to a hot water heater, along with some pretty good detail. In the case of the water heater in the example, you would save all of 25 cents if you left that water heater off for 8.5 days, more if you have a bad one, but pretty minor savings. I'm definitely curious about what the margin actually is for savings on an E61 class machine, particularly with insulated boilers. I'd imagine that turning it off for less than 2 hours or so saves you almost absolutely nothing. So, Ian, it'd be cool to see your graphs corrected and the difference calculated, if you care to rework the data with the corrected observation interval.

by **Ben Z.** on Thu Feb 04, 2010 11:54 am

another_jim wrote:My apologies for going ballistic; I thought it was some sort of provocation. But a web search turns up lots of people have made the same mistake about short turn offs not saving energy; not just for espresso machines and hot water heaters, but even for light bulbs.

It could be true for very short turn offs for certain devices which have a large draw at start-up. Certainly not for any purely resistive things like you mentioned.

by **shadowfax** on Thu Feb 04, 2010 12:37 pm

shadowfax wrote:Just a reminder—if you have cold winters, your huge espresso machine saves you a modicum of money on your home heating costs in those months. It's probably pretty minimal, but that all depends on your home's size, your heater's efficiency, etc. If you have hot summers and a crappy old air conditioner, leaving your espresso machine on all the time adds yet another source of heat for your air conditioner to counteract. This leads to increased HVAC costs in hot months.

As an addendum to all the fun in this thread, Jim dug me up an old alt.coffee discussion that covers similar ground and is a real gem. One part that grabbed my attention was Jack Denver's comment:

Jack Denver wrote:...the important thing is to recognize that in a cooling environment, any heat producing device (incandescent light bulb, etc.) costs somewhat more to run than the face value of its wattage. A truly accurate figure would be more like 1.4 /1 and since this is seasonal, an annualized figure would be even lower. The other thing to keep in mind is comfort...most homes have thermostats located away from the kitchen so unless you rebalance you dampers to put more air into the kitchen that room may end up uncomfortably warm if you add a 24/7 heat generator to it.

Jack provides some interesting guesstimates for the actualized cost you're likely to see for an espresso machine in your house, with the usual qualifiers (efficiency of A/C, how hot your climate is, etc., etc.). Anyway, there's some handy stuff in there for those interested.

by **sweaner** on Thu Feb 04, 2010 1:45 pm

shadowfax wrote:In the case of the water heater in the example, you would save all of 25 cents if you left that water heater off for 8.5 days

Nicholas, extrapolate this to the entire world. If we all turned our appliances off when we went on vacation I think the savings would be dramatic. Of course, even if I saved $5 I doubt I would turn it off. Remember, we usually use the water heater all day long.

by **Psyd** on Thu Feb 04, 2010 4:40 pm

Bluecold wrote:Yeah, strangely enough, some people rather believe well respected thermodynamics theory instead of some guys on the internets claiming the opposite, only substantiated by some pretty graphs and a couple of low insults. Please show me your perpetuum mobile when you're finished.

Wait, are you in the thermodynamics group, or the 'low insults' group? I'm having a hard time following.

Try to be patient with some folk. Some haven't the advantage of being familiar with the laws, some have trouble understanding that there is a zeroth law, and there are others that suggest that since some have claimed to have 'seen' absolute zero, the third law has been false all along, so how are we to depend on the rest so well?

On yet another hand, if someone states that something is impossible and point to a physical law to illustrate why it is impossible, and yet I observe said impossible thing occur in my kitchen on a daily basis, do I just accept that I'm an idiot or insane, or do I question the person's application and understanding of the physical law that he'd quoted?
Would you have any more respect for those people if they were simply to accept that it was true because someone said it on an internet forum?
Let's give some of the non-scientists a break, here, once in a while. If they make a mis-statement, show your math, he'p a brother HB 'er out, and move on with a friendly smile.

by **malachi** on Thu Feb 04, 2010 5:37 pm

The Information Age was dealt a stunning blow Monday, when a factual error was discovered on the Internet. The Onion


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