fredk01 Senior Member Joined: 20 Feb 2012 Posts: 116 Location: Canada Expertise: Just starting
Espresso: Saeco Aroma Grinder: OE Pharos
Posted Sun Mar 3, 2013, 8:19am Subject: Machine design and warmup time
Here is something I have seen mentioned occasionally, but not discussed directly.
Is there really any practical difference in heating time for machines with larger boilers, or do manufacturers take this into account when they design the machine?
JasonBrandtLewis Senior Member Joined: 9 Dec 2005 Posts: 6,099 Location: Berkeley, CA Expertise: I live coffee
Espresso: Elektra T1 - La Valentina -... Grinder: Mahlkönig K30 Vario -... Vac Pot: Yama 5-cup Drip: CCD, Chemex Roaster: No, no, not another...
Posted Sun Mar 3, 2013, 9:29am Subject: Re: Machine design and warmup time
There is a difference between having an espresso machine "reach temperature," in which case a light turns on or off, and having a machine reach a state of thermal stability. The light on my old Gaggia would turn on (or was it off?) after approximately five minutes, but it certainly wasn't ready to use -- it wasn't thermally stable yet. That took much longer.
Rule-of-thumb: the larger the boiler, the longer it takes for a machine to reach a state of thermic stability. More powerful heating elements can compensate for this to a certain extent, but . . . .
fredk01 Senior Member Joined: 20 Feb 2012 Posts: 116 Location: Canada Expertise: Just starting
Espresso: Saeco Aroma Grinder: OE Pharos
Posted Sun Mar 3, 2013, 10:25am Subject: Re: Machine design and warmup time
JasonBrandtLewis Said:
Rule-of-thumb: the larger the boiler, the longer it takes for a machine to reach a state of thermic stability. More powerful heating elements can compensate for this to a certain extent, but . . . .
That is my understanding. Being a techie, I always want to quantify. Working backwards,for a 15 amp circuit, the max allowable draw is ~1800 watts. I seem to remember for loading there should be a margin for safety that I think was around 70% or 80%. That would be 1200 to 1400 watts.
So, when I look at a dual boiler machine wired for a 110 15 amp circuit and the machine advertises 1300 watts, that would be for both boilers. Hmm...
So, two machines with one at 1300 watts for 2 liters vs the other at 1100 watts for .5 liters, this works out to 700 watts per liter vs 2200 watts per liter respectively. I guess the one with the smaller boiler might just heat up a little quicker. :-)
When you write 'thermic stability' are you including the time for the group to heat up as well? I'm not sure how much a cold group would affect boiler temp stability (I know it will affect shot temp stability).
JasonBrandtLewis Senior Member Joined: 9 Dec 2005 Posts: 6,099 Location: Berkeley, CA Expertise: I live coffee
Espresso: Elektra T1 - La Valentina -... Grinder: Mahlkönig K30 Vario -... Vac Pot: Yama 5-cup Drip: CCD, Chemex Roaster: No, no, not another...
Posted Sun Mar 3, 2013, 11:04am Subject: Re: Machine design and warmup time
My response will disappoint you. I am not a "techie" (despite using personal computers since the days of CP/M, which predated MS-DOS). I personally don't give a $#|+ for the technical aspect -- what I care most about is TASTE, how my espresso tastes in the cup.
Boiler temperature stability is irrelevant. Is the boiler hot enough (and large enough) to provide the steam I need? Yes? It's good to go! No? Grumble-grumble-grumble.
Group temperature stability is everything, as too-cold-a-cold group will ruin the shot, just as too-hot-a-group . . . .
calblacksmith Moderator Joined: 25 Nov 2007 Posts: 5,679 Location: Riverside, Ca, U.S.A. Expertise: I live coffee
Espresso: ECM Veneziano A1 Grinder: Many different commercial Vac Pot: 40s era Silex Drip: Milita, Bunn&Curtis... Roaster: Cast iron pan, gas burner
Posted Sun Mar 3, 2013, 11:49am Subject: Re: Machine design and warmup time
I am a bit of a tech geek and I am with Jason 100%. While I suppose what you are asking is relivant in some small way, it really has no bearing on stability and warm up time. When the boiler is"hot" is moot. What counts is when ALL the metal mass of the machine hits stability is what is important and that is different for every machine.
A rule of thumb though is a bigger boiler is more stable than a smaller one, there is just more thermal mass to keep things stable. A bigger or smaller heater will slightly affect how long this takes but not to any major degree.
For a home machine allow at least half an hour to warm up and for a semi commercial or commercial machine allow at least an hour. Any part of the machine that is not to temp, will suck heat from the machine on the whole so what small effeciit has on the boiler is moot. Machine temp stability is the goal, not one part at a time.;-)
Obsessing over minute details is fine but in the big picture it is about the same as wondering about how the lint in your navel affects your weight. Yes it adds to the total but it really does not matter all that much.
In real life, my name is Wayne P.
Feed the newbs, starve the trolls and above all enjoy what you drink!
Jmanespresso Senior Member Joined: 18 Jan 2009 Posts: 2,108 Location: Westchester NY Expertise: I live coffee
Espresso: Alex Duetto II Grinder: Compak K10 - Vario Vac Pot: Yama-SY5/SY8/TCA5 Drip: V60, Beehouse, CCD Roaster: Hottop B
Posted Sun Mar 3, 2013, 12:22pm Subject: Re: Machine design and warmup time
^^Both of those guys got it right. Its not just heating up the boiler and the group.. Its really heating up every part of the machine.
A solid rule of thumb- Single Group Machine-One Hour Multi-Group Machine-1 1/2 to 2hours, depending. A 4 group Linea needs longer to get fully stabalized then a 1 group does, but not proportionally longer. After an hour and half, a four grouper should be mostly up to temp. Home/Consumer machine-20-45minutes.
I leave my machine on 24/7. I always have. But, with my Dual Boiler, I switch the steam boiler off when Im done. Purely for the fact that I can, and because heating it up doesn't mean getting the whole machine hot again, the boiler just has to reach pressure. For my machine, its about 5 minutes give or take. Cafe's leave their machine on all the time as well. Can't be waiting two hours in the morning for the machine to warm up! Some of the top end leading edge machines are starting to add an "overnight" cycle to the electronics, which will run the machine in a lower power state to save energy, and keep the machine warm. Its not brewing temp, but it will reach brewing temp very quickly when you come in. Commercial machines that aren't seen in third wave Cafes that have fancy looking electronics have had these features for years(Rancilio, Wega, Spaziale...).. Its nice to see Synesso's and Marzocco's with them now.
Follow Your Bliss
Coffee makes your constantly overcome your prejudices and re-evaluate your own "received wisdoms" when it comes to judging cup flavors. -Tom Owen, SweetMarias
This is exactly what I was trying to get at. I have never seen it written before.
Often, people are encouraged to move up to a prosumer or use pro machine, even when the use is relatively light and I wonder why.
calblacksmith Said:
Obsessing over minute details is fine but in the big picture it is about the same as wondering about how the lint in your navel affects your weight. Yes it adds to the total but it really does not matter all that much.
My interest is not in how quickly the boiler heats up. I did however want to understand what Jason meant by thermic stability since he did not in any way define the context.
I want to understand the various tradeoffs involved in a used pro or prosumer machine vs. a smaller light use machine (specifically the CC1). A month ago, I would have picked up a used pro machine at the right price. Now, it strikes me that such a machine offers almost no value to me. Time to heat the whole system is just another nail in the coffin.
Thanks to everyone for your replies. Things are slowly becoming clear to me with respect to my needs and the right machine.
D4F Senior Member Joined: 15 Mar 2012 Posts: 1,192 Location: USA Expertise: I like coffee
Espresso: Gaggia Classic PID Grinder: Preciso
Posted Sun Mar 3, 2013, 2:10pm Subject: Re: Machine design and warmup time
I have a Gaggia Classic and PID. I have used another thermocouple in a couple of places on the machine to measure temperatures for other parts of my project. The PID controller will force a stable temperature quickly. Trouble is, the stability is the boiler itself, and actually only the sensor position on the boiler. I have an added power supply to an alarm function on the floor of the internals over the reservoir and it reaches near stability in 15 - 20 minutes and then raises about 2 more drgrees F in the next 15 minutes. 20 - 30 minutes is great, though the PID controller did not move temperature after about 5 minutes.
Looking at it from the brew water end, you can hit the steam switch and get hot water (200F) out of the group in about 5 minutes, but it is difficult to learn and reproduce. I found in practice that a 20 - 30 minute warm up will allow a quick second pull and 5 - 10 minutes will not. I have used a thermofilter in observations.
Long thread, but AndyPanda describes surfing the steam switch and using the machine with 5 minute warmup in almost steady instability. I used the PID and long warm up.
it has been written plenty on this forum and others, but goes overlooked very often.
Encouragement may not be the word I would use, if someone says their budget is $1000 for grinder and machine people do not for the most part say spend more. If however you want to spend a $1000 on a machine people may say that $300 extra may up you into a new class of machine that will last longer, posiable have more features, and may just be a better buy yet they often gives examples of specific machines and why for a bit more this machine might be a better buy.
fredk01 Said:
My interest is not in how quickly the boiler heats up. I did however want to understand what Jason meant by thermic stability since he did not in any way define the context.
A HX (or double boiler) machine that has 8-15lb of brass up front (the group head) is room temp on a cold machine and the water from the heated hx ( or boiler on a DB) passes through it. Thermal stability of the machine refers to the mass of the group warming to the amount it is going to warm to with the boiler set at the temp/pressure it is set to, the mass has become thermally stable. For instance my boiler has an offset of 18f warmer then what the pid reads so if my setting on the PID is 200 then my boiler is actually at 218f, this allow the water lines and the mass of the group to be warmed to a level so that 218f water from the boiler can reach the puck at 200f.
How quickly a boiler warms up to its set point is straight forward, watts to volume. my Duetto duel boiler in 15amp mode shares duty, the 1.8L steam boiler gets 1200 watts but the 800 watt .8L brew boiler takes precedent, in 20 amp they both can be on. My NS Oscar HX machine needed to be on for 52min I believe to become thermally stable, I measured this with a Kill a Watt and timed the cycles the heating element was on, 52min ( or there a bouts) was the time it took for the time the elements where on and the time being off stabilized, up until that point the element is on for longer and off for shorter.
fredk01 Said:
I want to understand the various tradeoffs involved in a used pro or prosumer machine vs. a smaller light use machine (specifically the CC1). A month ago, I would have picked up a used pro machine at the right price. Now, it strikes me that such a machine offers almost no value to me. Time to heat the whole system is just another nail in the coffin.
Thanks to everyone for your replies. Things are slowly becoming clear to me with respect to my needs and the right machine.
Keep reading, keep questioning, I only know what I know because of this community and the desire to keep learning about everything coffee. I don't call an extra 30min warm up time a tradeoff if I get something back for the extra time. As far as I have seen so far the CC1 is still working out stability in delivering consistent shot temps. I know steps have been taken to improve this but do not know the results.
Sorry. I didn't realize it was such a mystery . . .
fredk01 Said:
I want to understand the various tradeoffs involved in a used pro or prosumer machine vs. a smaller light use machine (specifically the CC1). A month ago, I would have picked up a used pro machine at the right price. Now, it strikes me that such a machine offers almost no value to me. Time to heat the whole system is just another nail in the coffin.
My Elektra T1 (home machine) has a 6.0L boiler. From a cold start, it will take at least 75-90 minutes. But since it's on 24/7, I can walk up to it at any time of the day or night and pull as many or as few shots as I need to make. My La Valentina (office machine) is on an automatic 7-day programable timer -- many of us have our machines on timers -- to switch on at 8:00 am and off at 6:30 pm, Monday through Friday. That way, when I get to my office at 9:00, everything is "good to go." Thanks to everyone for your replies. Things are slowly becoming clear to me with respect to my needs and the right machine.
Jmanespresso Said:
^^Both of those guys got it right. Its not just heating up the boiler and the group.. Its really heating up every part of the machine.
Any machine needs to be thermally stable in order to produce the best shot possible, and that either takes time, or it takes being on a timer.
A "prosumer" machine is more reliable and dependable, and generally built with professional/commercial parts, than a home (consumer) machine. But equally important is the grinder. (See "The 4 M's of Espresso" and "Babbie's Rule of Fifteens".)
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