# Energy Monitor



## skenno (Oct 14, 2012)

Just wondering if anybody's used an energy monitor to check the power consumption of their machine? Or can recommend one for me to buy?

I'm working from home at the moment so I tend to leave the Rocket on quite a bit during the day so it'd be good to have a rough idea how much it's costing me (are we talking pounds or pennies?!).

Also due to be on paternity leave any day now so I may end up having it on 24 hrs a day while I'm off!


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## aphelion (Nov 23, 2012)

Yep, i'm also quite interested in this since buying my Fracino.

Its quite a sizeable unit (boosting a 2 litre boiler every minute can't be that cheap to run..)


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## The Systemic Kid (Nov 23, 2012)

skenno said:


> Just wondering if anybody's used an energy monitor to check the power consumption of their machine? Or can recommend one for me to buy? I'm working from home at the moment so I tend to leave the Rocket on quite a bit during the day so it'd be good to have a rough idea how much it's costing me (are we talking pounds or pennies?!). Also due to be on paternity leave any day now so I may end up having it on 24 hrs a day while I'm off!


We've just been switched to new gas and electricity meters with a console. Was told it tells us exactly what we're using, energy-wise, and the real cost. Been meaning to check what it costs to leave the LI on for several hours. Will do a test and report back.

Best of luck with your mat leave - the coffee will go some way to compensate for the sleep disturbance.


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## Steve_S_T (Dec 7, 2012)

This is something that I've been wondering about too, just haven't got around to buying a meter and setting it up. I'd like to weigh up the cost of heating it up from cold against the per hour cost of maintaining the heat as I'm always in a quandry about whether to leave my Heavenly on for 4 hours, for example, after lunch and before I get home, or whether to switch it off and fire it up again. I reckon that leaving it on is probably more cost effective, plus it eliminates the waiting time for warm up so I'm ready to pull a shot as soon as I get home, but I'm not entirely convinced. We used to be told that starting a car engine uses more fuel than leaving it idling for 5 minutes, now some "green branded" cars switch off automatically at traffic lights to save fuel!

Steve.

P.s. Enjoy the paternity leave Skenno, it will be a most amazing time of your life and will be a hazy, blurry whirlpool of visitors and emotion with or without caffeine!


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## series530 (Jan 4, 2013)

Being in the electronic test business, measuring power is in my blood.

With the Cherub, the power consumption is 2850W when initially turned on. This is about the same power consumption as a high performance kettle and is limited by the 13A fuse in the mains plug.

The system goes through a reasonably lengthy heat cycle while the boiler is heated up. Even if that lasted for 20 minutes (which it doesn't) it would cost you about one KWh of electricity (one unit) (perhaps 15p on a typical tariff). Once warm the standby power is about 2.5W (you could run for 16 days before it would cost you 1 KWh). The unit will pulse on an off infrequently while it maintains temperature (the boiler doesn't appear to be insulated). As a guess, it's probably off for 95% of the time and on for 5% of the time. Thus, over a 1 hour period, it will consume about 140Wh of power and over the space of about 7 hours you will consume about 1KhW of power.

Obviously, using the unit will consume power both by pumping water through the boiler and the need to reheat. As you are not running a coffee shop at home, this activity will be infrequent but you need to factor this in. The pump draws about 75W while running. This will only be over a short cycle while pumping fluid through to the boiler/heat exchanger.

Of more concern, I would imagine, is the fact that the unit is always on and components will be subject to some degree of electrical, fluid and thermal stress. I would hope that the unit is designed such that the MTBF (mean time between failure) is suitably high enough so as to not cause major repair costs.

If you want to buy an energy monitor I can whole heartedly recommend one of these

http://www.maplin.co.uk/plug-in-mains-power-and-energy-monitor-38343

It's reasonably cheap, is far more accurate than many other units on the market and is pretty robust. Simply set it to KWh (the yellow button) and read off the totals. 1KWh is one electricity unit. You can calculate the cost of a unit from your electricity bill.


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## Shady (Jan 1, 2013)

Congratulations on your impending arrival. Having just returned to work from my paternity leave my advice would be stock up on coffee as consumption is inversely related to the amount of sleep you get (I was on 4 to 6 doubles a day).


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## skenno (Oct 14, 2012)

Thanks all. Sounds like it probably isn't as expensive as I feared. I've got a maplin near the office so I'll take a look when I'm next in.

I've already got a two year old so it would be handy if I could train him to make my coffees for me when I'm too tired to - but I just don't think he'd use enough tamping pressure! He does shout 'morning time! Let's make a coffee! Espresso for daddy!' When he wakes up though so he's heading in the right direction!


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## Steve_S_T (Dec 7, 2012)

Thanks for that info Series530. I've just had a chat with a helpful guy at Fracino about getting a hot water outlet fitted to my Heavenly. As we make tea and other hot drinks fairly infrequently it would appear from your info (to me at least) that using a hot water outlet on the Heavenly for those odd drinks will be a cheaper option than re-boiling a cold kettle.

Steve.


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## series530 (Jan 4, 2013)

I suppose it could be argued that to raise the temperature of something you need to heat it and to heat it consumes power. In effect, you are transferring the consumed power into a heat rise.

If you heat an insulated vessel vs. heating something like a kettle (which isn't insulated), overall, to maintain the temperature requires less power. The problem is that the Cherub doesn't appear to be insulated so, to my thinking, it takes about as much energy overall to keep a cherub heated as it does to keep a kettle hot (not that you would). Add to this the fact that by keeping it turned on you are stressing the unit and risking calcium build up (if you live in a hard water area), you may be better off simply boiling just enough water for your infrequent drink than maintaining a whole Fracino boiler full of heated content for an occasional drink.

Plus, if your kettle breaks down you can buy a cheap and cheerful new one at Currys for a whole lot less than the cost of sending your espresso machine to Birmingham for repair.

Most of us need a kettle anyway. I think I would err toward using the kettle except when I want to drink some decent coffee.


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## skenno (Oct 14, 2012)

I noticed quite a drop in boiler pressure when using the hot water tap on mine to make 2 cups of tea, so I stick to the kettle now. It's handy to have the tap for warming cups, descaling and maybe the very occasional tea, but I could live without it. Your machine may be different though, I suppose if it could happily manage a few teas without affecting the coffee making/steaming it would be more useful.


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## Steve_S_T (Dec 7, 2012)

Take your points. I would still use the kettle if I was making 4 hot drinks, but on most days there is a point (if I'm at home) when the children arrive home from school where I will make 3 espresso based coffees for the wife, myself and our daughter and a tea for my lad. In that case it would feel easier and, I suspect more cost efficient, to just grab the water for the tea from the Heavenly. It's academic at the moment anyway as I don't have a hot water outlet, although I must admit I'm quite impressed that it will "only" cost around £80.00 to have one fitted, although that's based on the fact that I only live 15 miles from Birmingham and Fracino. If I book the machine in in advance I can drop it off at an allotted time, head into Brum for a couple of hours then collect it on my way home. Very tempting I must say. Next time it crops up in a thread I'll tell you what he said about descaling









Steve.


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## series530 (Jan 4, 2013)

Steve_S_T said:


> Take your points. I would still use the kettle if I was making 4 hot drinks, but on most days there is a point (if I'm at home) when the children arrive home from school where I will make 3 espresso based coffees for the wife, myself and our daughter and a tea for my lad. In that case it would feel easier and, I suspect more cost efficient, to just grab the water for the tea from the Heavenly. It's academic at the moment anyway as I don't have a hot water outlet, although I must admit I'm quite impressed that it will "only" cost around £80.00 to have one fitted, although that's based on the fact that I only live 15 miles from Birmingham and Fracino. If I book the machine in in advance I can drop it off at an allotted time, head into Brum for a couple of hours then collect it on my way home. Very tempting I must say. Next time it crops up in a thread I'll tell you what he said about descaling
> 
> 
> 
> ...


Oh, go on, .... tell us now. I'd like to know !


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## Steve_S_T (Dec 7, 2012)

He said ........................................................ don't do it.

Steve.


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## series530 (Jan 4, 2013)

Did he give a reason or any suggestions of how to deal with inevitable calcium build up (no water being totally calcium free) ?


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## Steve_S_T (Dec 7, 2012)

Basically he told me that using filtered water not only helps to prevent scale forming but also it partly dissolves existing (not entirely convinced). However, another reason that they don't recommend descaling is because of how difficult it is to ensure that all of the water/ descaler mix has been flushed and purged from the system afterwards, and I certainly can see that argument as it's something that I have been musing over (and indeed started a thread about). Personally I'm reluctant to go for extended periods without descaling, but in fairness to the guys at Fracino they don't sell descaler on their website so that indicates they mean what they say, the basic (flawed?) argument being that descaling will loosen scale (that's the idea isn't it) and therby cause a problem. Hmm, I'll be interested to hear what others think.

Steve.


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## The Systemic Kid (Nov 23, 2012)

series530 said:


> Being in the electronic test business, measuring power is in my blood.
> 
> http://www.maplin.co.uk/plug-in-mains-power-and-energy-monitor-38343


Decided to test power usage on My LI using the Maplin monitor above. LI has the same power consumption as the Cherub (2850W) - boiler is 2.3 ltr. Room temp whilst I was measuring power consumption was 17c - not exactly warm!

LI took 4.5 minutes to get to operating temperature (1.3bar) . Once there, thermostat would kick in for approx six seconds every minute. Over the course of 30 minutes, the energy monitor showed power consumption of 0.11 KWH so that's 0.22KWH for a full hour. Please note, KWH consumption did not include heat up time. I plugged in the monitor after the machine had fully warmed up and settled down. By my calculations of 12.44 pence per kilowatt, LI consumes about a fifth of a KWH - about 3p when its idling. Warm up time of 4.5 minutes costs about 16.5p. Think I've got my maths right.


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## Steve_S_T (Dec 7, 2012)

So if I turn on at 7 am and off at 6pm (that's my normal Saturday routine) I'm spending about 50 pence in electricity? In which case I'd estimate a cost of about £10.00 per month to run. More than I hoped, but not a deal breaker. Also I read those figures as indicating that unless you're turning the machine off for more than 5 or 6 hours it's cheaper to leave it on.

Steve.


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## lookseehear (Jul 16, 2010)

The Systemic Kid said:


> Decided to test power usage on My LI using the Maplin monitor above. LI has the same power consumption as the Cherub (2850W) - boiler is 2.3 ltr. Room temp whilst I was measuring power consumption was 17c - not exactly warm!
> 
> LI took 4.5 minutes to get to operating temperature (1.3bar) . Once there, thermostat would kick in for approx six seconds every minute. Over the course of 30 minutes, the energy monitor showed power consumption of 0.11 KWH so that's 0.22KWH for a full hour. Please note, KWH consumption did not include heat up time. I plugged in the monitor after the machine had fully warmed up and settled down. By my calculations of 12.44 pence per kilowatt, LI consumes about a fifth of a KWH - about 3p when its idling. Warm up time of 4.5 minutes costs about 16.5p. Think I've got my maths right.


Doesn't sound quite right to me!

4.5 mins at 2.85 kW is 0.21 kWh or at 12.44p/kWh that's only 2.66p for the warm up then another 2.7p for the first hour keeping it hot. That means that it would cost you per hour (ignoring pump power etc - purely heating):

H1: 2.7p warmup + 2.7p maintaining the heat (5.4p total)

H2: 2.7p maintaining (8.1p total)

H3: 2.7p maintaining (10.8p total)

H4: 2.7p maintaining (13.5p total)

If you imagine that you wanted to make coffee at the start of the day then again after 4 hours you have 13.5p from the above or if you switch off after the first coffee then switch on again after four hours (another 2.7p in warmup costs) you've only spent 5.4p total.

Also, from reading on HB about this, I'm pretty sure that its actually a violation of physics for it to be more efficient to keep a hot body hot than to let it cool then reheat later!


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## series530 (Jan 4, 2013)

I ran a test last night:

I have my energy monitor directly connected to the 13A socket and the grinder and espresso machine connected to this. Having reset the monitor I turned on the Cherub and let it warm up for about 40 minutes. I then made a mug of tea using the hot water outlet, ground about 18g of beans with the Mignon (which takes approximately 250w when operational and 1.8W when in standby), warmed a large cappuccino cup and prepared a cappuccino using the group head and the steam wand (starting with cold milk). I then flushed the head and cleaned the wand and powered everything down.

In all 337Whr and a cost of 4.96p.

It still wouldn't convince me to keep the machine on all day for the reasons given previously. It does demonstrate, to me at least, that running costs are pretty low for a Cherub. Certainly, the coffee and the milk costs far more than the power.


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## espressotechno (Apr 11, 2011)

When talking to commercial customers about their espresso machine & likely demand for hot water for tea, etc., I always remind them that an espresso machine is a coffee-making machine - NOT a tea machine. Too much hot water drawoff results in a drop in boiler temp. as the boiler refills & a consequent drop in steam pressure.

If they expect to be selling lots of teas, I suggest a separate hot water boiler (eg Bravilor)


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## ronsil (Mar 8, 2012)

espressotechno said:


> that an espresso machine is a coffee-making machine - NOT a tea machine.


Thats for sure. For home use do not use as a very expensive kettle.


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## Pdalowsky (Dec 31, 2012)

would be interested to hear if anyone does this with the classic too, imagine it would be cheaper than these more elaborate units


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## skenno (Oct 14, 2012)

I've been using a belkin monitor for a few days now. It doesn't seem to record total energy used, it just shows current energy use and then an average cost per month and year, so here are my incredibly unscientific results so far..

On average I think (told you it was unscientific!) I've been leaving the machine on for 2-3hrs at a time for a total of 6ish hrs a day and probably making 3-6 drinks each day. This is showing a cost of £76 a year (apparently based on an average rate for the uk).

If I get time tomorrow, I'll set an accurate cost amount and start recording how I'm using the machine to give a more accurate idea.


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