We love the Izzo Vivi PID. In fact it’s one of our favourite heat exchanger (HX) machines.
There’s not much not to like:
- Simultaneous shots and steam like all good machines
- PID temperature control
- Superb external finish and internal build
- Stainless chassis
It’s a terrific, compact espresso machine but like all e-61 HX machines, it could be better. In fact, if it was made to be really, really smart, it could make a dual boiler machine redundant. Turns out that if you have a heat exchanger machine and feel it’s time to upgrade to dual boiler, there’s a really compelling alternative to consider customisation rather than the sale of your machine.
The nature of the HX is that if you want temperature control at the group, it comes at the expense of poor steam at lower boiler temperatures or a cooling flush if you run the boiler at higher pressure. Shot, steam and boiler temperature are are linked to each other. In addition, this style of machine usually requires a 30 minute warmup before use. You can have a warm boiler, cool group and lousy coffee as a result.
How does the e-61 group operate?
In a HX machine, the group is heated by the thermosyphon- effectively a circuit of warm water from the HX. Warm water enters the group from the top of the HX and cool water leaves the group and returns to the HX. Restrictors can be used to control the flow of water to the group and they are important. The boiler may well be at 125deg C, but coffee needs to happen in the mid 90s: you need to shed heat. A bonus with the use of restrictors is that a large cooling flush can be required in a group at over 100 deg.
When you’re pulling a shot, cool water enters the HX from the tank or mains and with a few smarts, you flash heat the water sufficiently to get the desired mid 90’s at the group. Design that HX poorly and you have a machine which runs too hot or too cold…
Reimagining the e-61 HX group: What about if you could achieve dual boiler shot temperature control AND have consistent great steam?
Turns out you can, and when you do it, you get a HX machine with superior temperature stability to that of a dual boiler machine.
This is where the smarts come in. If you were to remove the group and restrict the thermosyphon substantially, you have a a machine that naturally runs cold. Then you heat the group independently….
Cartridge heaters. Our Izzo Vivi Plus PID Red Series employs dual cartridge heaters to the group. These heat the group independently and a bonus is that when you have heaters in the group, you also get a machine which is fully heated and ready to use in under 10 minutes! No more timers. There’s also no need to leave the machine on all day in case you want a coffee. If it’s been on in the last couple of hours, you’re up and ready and rapidly: Read significant energy savings.
So what changed?
Turns out it was a fair bit changed: Our Vivi Plus PID Red Series scored a PID replacement from its dual boiler Alex Duetto sibling to allow for a seperate channel to control the cartridge heaters. A second relay and some wiring was also required. The group was precision drilled to accommodate two cartridge heaters and a thermocouple to complete the feedback loop. This allows for precise temperature control of the group for light roast coffee, dark roast coffee- you name it!
Our cartridge heaters react far more quickly than any dual boiler e-61 machine can. We get far more consistent temperatures and can change temperature much faster. Our Vivi Red series has superior steam performance when compared to the original donor machine as well as the boiler can be run at a higher temperature. The only visible difference to the original machine is that two temperatures cycle on the PID. We see boiler temperature as well as group set temperature.
So the overall result? They say red goes faster and here’s the proof….
The The Izzo Vivi Plus PID Red Series. It’s all pros and no cons. Sorta makes a dual boiler machine redundant, doesn’t it?
We thank our great mate Rick Bond aka The Coffee Machinist for making yet another fantasy become a reality.
Check out our happy snaps…