'La Spaziale difference'

[coffeeowl]

Here is interesting article about La Spaziale group design.
As far as I remember correctly a discussion a while ago, it is some kind of a heat exchanger system and it is not used in S1 Vivaldi (I don't remember where I read about it, it was some two months ago when I was browsing around in search for machine). Comments?

EDIT: And here about the hx

EDIT2 :)

EDIT3: So I made a little mess, for those articles I mentioned are about non-dual boiler machines like s5 and not about Vivaldi. Sorry

[Niko]

EDIT3: So I made a little mess, for those articles I mentioned are about non-dual boiler machines like s5 and not about Vivaldi. Sorry

Damn...you almost had had me on another roll. It would've generated at least another dozen posts out of me alone

[coffeeowl]

OK Niko, could you please comment, since I'm really curious - my seller says that the Vivaldi's design is the one mentioned in the 'La Spaziale Difference' article.
By the way... :) my machine is already here and today I've had my first cappucino in my life. MMMmmmmmmm it was good, good good. But I still like espresso more anyway

[wgaggl]

OK Niko, could you please comment, since I'm really curious - my seller says that the Vivaldi's design is the one mentioned in the 'La Spaziale Difference' article. That article is misleading with regard to the S1 Vivaldi.
By the way... :) my machine is already here and today I've had my first cappucino in my life. MMMmmmmmmm it was good, good good. But I still like espresso more anyway

No, the S1 Vivaldi is not a HX machine, it's a dual-boiler machine (which you don't need with the HX, as that would produce brewing water and steam within one boiler). I know I saw a cross-section through group and group-boiler somewhere but the link slipped my mind (anyone else please). That article is misleading with regards to the S1 Vivaldi.

It's much simpler than the HX, really just a small boiler kept at brewing temperature by PID (hence no HX tube needed) and directly bolted onto a solid metal group with the 3-way valve in between the water-path from boiler to group. The "La Spaziale Difference" here is really the narrow temperature range the brewing boiler water is kept by using a small brewing boiler boiler (separate steam boiler), powerful heating element, precise temperature probe, compact design (boiler bolted to group) and a well-tuned PID.

Wolfgang

[Niko]

Yeah!




...
I don't know how I fell asleep on this one.

[wgaggl]

Yeah!

...
I don't know how I fell asleep on this one.

Great use of emoticon, Niko.

Happy Holidays,

Wolfgang

[coffeeowl]

Yes, I only thought (I was told so by my supplier shame on him) that Vivaldi uses a HX to preheat the water coming to brewing boiler, which of course is not true as it would demand the steam boiler to be on all the time.

[wgaggl]

There is no active preheat of the brewing water with the S1.
What I found however, when the supply water and environment temperature are very cold (like in our kitchen during winter) I really have a flatter brewing temperature profile with the steam boiler on. After all the steam boiler radiates heat through the machine and helps to prevent heat loss from all parts of the water path. This effect however isn't very strong.

Wolfgang

[Niko]

I take it you didn't insulate your steam boiler, Wolfgang.
You mean to tell me you didn't join in on the boiler wrapping party of '07?
...I skipped that one too

[wgaggl]

I take it you didn't insulate your steam boiler, Wolfgang.
You mean to tell me you didn't join in on the boiler wrapping party of '07?
...I skipped that one too

Yeah, I decided not to insulate the steam boiler. There would be some energy saving and less steam boiler cycling with insulation, but when I found there's a (even just marginal) chance for more temperature stability with that steam boiler on (in cold environments at least) I voted against insulation...

Regarding energy usage, as I don't have the S1 running 24/7 that's not really an issue anyways.

Wolfgang

[wgaggl]

One more thought, regarding group boiler insulation:
That really doesn't improve temperature stability at all. The PID parameters are set based on typical heat-up (heating element) and cool-down (cold water inflow and heat-loss) values. Without heat-loss overshoots in heat-up take longer to correct.

Wolfgang

[Richard]

The PID parameters . . . .

Documentation, please, for the existence of a PID system in the Vivaldi?

[wgaggl]

The PID parameters . . . .

Documentation, please, for the existence of a PID system in the Vivaldi?

Ouch, you're absolutely right, Richard.

In my defense, I just worked on temperature measurements with a nice 2-group GB5.
Also was pondering about the recent steep price increase for the GS3.
So you see, I was in "PID-Mode".

To correct myself:
The S1 has a delta-controller (also called deadband or two-point controller).
And BTW, a delta-controller is a safe recipe for over-shoots anyways...

The PID for the Vivaldi was just my wishful thinking.

Thanks for the reminder,
Wolfgang

[Niko]

As we said before, Wolfgang...
PID'ing the Vivaldi wouldn't really improve anything, right?
We were talking about this on another thread and you were one of the guilty parties :D

[wgaggl]

As we said before, Wolfgang...
PID'ing the Vivaldi wouldn't really improve anything, right?
We were talking about this on another thread and you were one of the guilty parties :D

Absolutely right, Niko.

[chas]

So are you saying that, while it's not a PID, it's as good as a PID the way LaSpaz has implemented it?

[wgaggl]

So are you saying that, while it's not a PID, it's as good as a PID the way LaSpaz has implemented it?

I believe this was discussed a while ago (I'm not in the mood to search the board now).

Doing temperature profile measurements with my digital Fluke datalogger (coffee in the basket, temperature measured every second at top of puck, either immediately after previous shot or 50ml blank shot and wait till boiler has cycled), the typical 95% confidence interval (approx. 2*StdDev) for the temperature was about 0.95 degC for 5sec into the shot until end.
The Synesso Cyncra for comparison with the same technique achieved a 0.6 degC confidence interval (based on the measurement technique you will get different results of course). However, the Cyncra reached the programmed temperature about 2sec into the shot.

The point here is, that a PID for the S1 would not significantly improve stability, it is already great compared to other machines for the flat part of the shot profile. A much stronger factor is the group design: An active group (either water or even with electrical wire running around group) would have a strong impact on the first 5 seconds, that's where the S1 is not as constant in comparison to LMs and Synessos.

So, that's enough for today, I need to get in Christmas mindset now :)

Wolfgang