Why PID an HX Machine?

Need help with equipment usage or want to share your latest discovery?
User avatar
TimEggers

#1: Post by TimEggers »

...split from Quickmill Anita vs. Alexia vs. Vetrano by moderator...


I see that Chris has a link to a PIDed Anita. I can understand the pros to having a PID on a single boiler machine, but on an HX is it really needed? Doesn't it offset the ability to steam on demand (I know it reduces the need for cooling flushes)? Help me understand the reasoning behind a PID on an HX.
Tim Eggers
http://www.facebook.com/TimEggers
LMWDP #202

User avatar
Compass Coffee
Sponsor

#2: Post by Compass Coffee »

Personally I believe there could be a couple reasons or whys to PID'ing an HX. One could be to simply make boiler temp/pressure changes easier experimenting with different settings for flush versus steam power trade-offs. Also SSR & PID likely more reliable long term than pstat from a failure point of view.

Some have used PID on HX machine to attempt to use their HX machine like a single boiler machine. This may or may not work well depending on the machine and willingness to trade steam power for less flush. However I believe most prosumer HX machines dialed down for almost no flushing won't be as shot temp stable as a single boiler machine like Alexia. HX machines are designed to have their boiler up at steam temp with the boiler heating the HX line! (I don't consider Ken's Junior in the category of most prosumer HX machines :wink: }
Mike McGinness, Head Bean (Owner/Roast Master)
http://www.CompassCoffeeRoasting.com

Beezer

#3: Post by Beezer »

I tend to agree that PID'ing an HX is kind of silly. It defeats the purpose of getting an HX in the first place, which is to have the ability to brew and steam back to back. If you PID the boiler and set it for ideal brew temp, it won't steam well. If you set it for steam temp, then you might as well just stick with a stock p-stat and save some money. If you really want that much control over brew temp, get a nice PID'd single boiler like the Alexia, or a double boiler with digital controls like the Brewtus or La Spaz.

In any event, most HX users seem to think that it's not too hard to get decent temp management on their machines by flushing more or less water before pulling a shot. I'm just getting used to my new Anita, but I find flushing to be the least of my problems. Right now, I'm having more trouble getting my distribution and dosing right.

User avatar
cafeIKE

#4: Post by cafeIKE »

If one plans to PID an HX, one must choose wisely.

A large boiler, heating capacity and massive group are absolute musts.

When I changed from the Solis SL-90, my plan was either dual boiler or an HX PID. In the end, after much data collection and analysis, I chose the Vibiemme Domobar Super Levetta. It's a tad less pro than Ken's Jr, but the project is a complete success. Details here

The machine needs to warm up for 1 hour before use. I made my first sink shot in months the day after the time change because the missus said she changed all the clocks... she forgot the timer on the VBM. :roll:

Shot to shot consistency is excellent, better than ±1°C, and no flushing whatsoever is required. I make straight doubles weekdays and lattes for the missus on the weekend. This past weekend we had a dinner party and I made 1 latte, 1 dry cappuccino and 2 macchiato in under 10 minutes, steaming the milk as I pulled each of the 4 double shots. Boiler pressure is a bit on the low side, about 0.7bar, but more than adequate for single drink steaming.

NOTE : This performance may or may not be obtained on other HX machines with smaller boiler, lower heat capacity and less massive group. Choose wisely.

SLC

#5: Post by SLC »

Beezer you just nailed it all in two paragraphs. Well put.

Single boiler, hx, double boiler. They all have there advantages and disadvantages. I the "barista" am the one that has to improve.

With my HX flushing has become a thoughtless task within the routine. Distribution and grind are where I mess up.

Mark

User avatar
danblev

#6: Post by danblev »

Take a look at http://www.coffeegeek.com/forums/espresso/machines/2272

A HX pstat has a dead band that is usually set to 0.2 bar which translates to 3 deg C. This temperature change affects your coffee. So after getting to know your machine you start temp surfing + flushing routine.

The PID only gives you better control and you need only to work on the flushing routine.

Ken Fox wrote on this topic Should I PID my Heat Exchanger?.
-
Danny

User avatar
Compass Coffee
Sponsor

#7: Post by Compass Coffee »

danblev wrote:A HX pstat has a dead band that is usually set to 0.2 bar which translates to 3 deg C. This temperature change affects your coffee. So after getting to know your machine you start temp surfing + flushing routine.
Danny
Maybe usually, or rather some pstats have 0.2 bar deadband, some have 0.1bar deadband and Barksdale pstat (which I'm using) has 0.05bar deadband which translates to about 1f.
Mike McGinness, Head Bean (Owner/Roast Master)
http://www.CompassCoffeeRoasting.com

podo98

#8: Post by podo98 »

...merged similar topic with prior thread by moderator...



I have read many of the posts and I am still a bit confused about the advantages of PID'ing a Quickmill Andreja. Can someone explain how the PID improves life over a non-PID'd machine. What are the pros and cons? Does it matter less because the Andreja is a HX machine versus a machine like the Silvia or the Alexia?

Brett

gscace

#9: Post by gscace »

Beezer wrote:I tend to agree that PID'ing an HX is kind of silly. It defeats the purpose of getting an HX in the first place, which is to have the ability to brew and steam back to back. If you PID the boiler and set it for ideal brew temp, it won't steam well. If you set it for steam temp, then you might as well just stick with a stock p-stat and save some money. If you really want that much control over brew temp, get a nice PID'd single boiler like the Alexia, or a double boiler with digital controls like the Brewtus or La Spaz.

In any event, most HX users seem to think that it's not too hard to get decent temp management on their machines by flushing more or less water before pulling a shot. I'm just getting used to my new Anita, but I find flushing to be the least of my problems. Right now, I'm having more trouble getting my distribution and dosing right.
Hi:

Be careful when you generalize. There is are advantages to PID control of hx machines and they are the same as for double or single boiler machines, namely eliminating temperature oscillation within the deadband and providing a convenient way of raising or lowering brewing temperature. Your third sentence in the first paragraph is just plain wrong. A great example of this is the Simonelli Aurelia.

I would also say that most people think it's not too hard to get decent temp management with hx machines because they haven't had extensive experience with something better. Get your hands on a La Marzocco GB5 or Synesso and spend some time with it and you will hate the water dance BS. Re your sentences 2 and 3 pf paragraph 2, once your technique is dialed in, reproducibility in other aspects of your system will become limiting. I think that once you experience the ease of control that modern industrial controllers give you, you will change your mind.

-Greg

Ken Fox

#10: Post by Ken Fox » replying to gscace »

What he said.

And, pressurestats by their very nature are inconvenient to adjust. If for no other reason, the ease with which I can change the boiler temperature of my two PID'd machines, is enough to justify the expense and aggravation of PIDing them. P-stats are so inconvenient to adjust in almost all cases, that they are set and forgotten. With a PID I can bias my machines towards the production of milk drinks or straight shots, and just as easily bias it in the other direction for my next drink or set of drinks.

ken
What, me worry?

Alfred E. Neuman, 1955