Preheat coils upgrader for Gaggia Classic (Pro) introduction

Such a great idea!!!! I was looking at your tables and would guess that with lungo hot watter output even exceed what was anticipated due to the OPV throwing the excess watter above 9 bar back into the cold watter tank ...

[@simondalton7488]

Fantastic work, my boost box is still going strong. I will consider this!

[@kgak1008]

I insulated my boiler and redesigned it to take a pid where the fill funel went I just 3D printed a piece to take its place it's like like 100% better also added a very nice switch to override the solenoid so j could have proper pre infusion but insulating the boer made a massive difference it's stays so thermaly stable now and I was able to fit it all in the factory chassis nothing hanging off the front side or back

[@horvathpeti84]

Hi, Thank you for sharing. Insulating the boiler is not gonna help with heat loss at all, the boiler loses majority of it's heat to the influx of cold water not the air surrounding it and that you can't insulate against, another big part is lost to all the other metal bits it contacts and maybe a very tiny almost unnoticeable part will be radiated int the air, for your brew cycle that's most likely nothing and you surely ain't gonna preserve more heat by insulating it. However insulation provides protection for the PID you installed inside the machine, which isn't recommended as they tend to overheat there if the machine is on for prolonged time. As it's quite far from the boiler and close to the vent holes, you're probably fine though. In terms of how nano heating works it's diff from stm, more static, less reactive, i'd leave the defaults in place if i was you.

[@kgak1008]

I hate to tell you this but you could not be more incorrect the boiler is far more stable in temp as a boiler tech I have a good understanding of thermal dynamics the temperature is far more stable under pulse width I think alot of this has to do with the type of PID and algorithm you set as well as the placement of the thermistor and of course the insulation prevents the casting from loosing a large percentage of its heat to the environment but I do agree the water does the bulk of heat loss in my opinion 60% but without question the coffee and heat stability has been dramatically improved

[@theretsum]

Really good mod, what should be considered in my oppinion is the etxra insulation of the coil, and an expansion buffer to reduce the stress and vibration. Good start btw

[@BREWBETTER]

Hi, Thank you. I've done an insulating for it out of high density closed cell silicone sponge sheet. Mainly because of the noise generated by the vibration, but it didn't make a lot of difference. It sounds much quieter when the Pro OPV is used with the braided silicone hose, instead of the version 1 brass OPV and the teflon tube. Especially if a pump dimmer is used too, it could be surprisingly quiet. In my opinion the heat dissipation of an expansion would be quite significant and it would definitely make it much more expensive, but I haven't tested it. In regards of stress, it is more than sturdy enough for even the double of the stress it gets. The heat insulation would definitely reduce power consumption though. I might try different materials, due to space limitations between the coils and the solenoid.

[@espressorestomelbourne1735]

loved the used of data for the why explanation.

[@thedude4795]

amazing

[@d4rk_entityy]

do you still sell this

[@SC-ch3cb]

Have you though about an all copper boiler for Gaggia classic?

[@BREWBETTER]

I have some ideas for years now, but it would be extremely difficult to put something together for a sensible price.

[@donniep90]

Like making a bigger boiler from another machine fit ?

[@chris9923]

Hello. Are you managing to get the temperature in the coil consistent from one shot to the next? How do you know it's not say 60 degrees one shot and 70 degrees the next? I'm really keen to improve the temperature stability but wary that this might be at the expense of consistency from one shot to the next. How are you getting on with this? Thanks

[@BREWBETTER]

Hi, Sorry for the delay in responding. I'm doing temperature testing eversince. I wanted to make a video about this in more details anyway, now I'm capturing all the data needed. I equipped a machine with multiple temperature sensors on the coils and also using a puck temperature sensor to see the output temperature. At this point I can say the entire system (group & preheat-coils) has to reach equilibrium before pulling a shot, otherwise the coils sucking so much heat from the system, it would completely ruin the temperature of the shot. This takes a warm-up time of 17 minutes from cold @ 24°C room temperature and interestingly 15 minutes to recover between shots.

[@BREWBETTER]

Obviously this is only relevant to my exact setup. If you do your own coils, your miles will vary.

[@yasinunlu443]

@@BREWBETTERInteresting. I thought the whole idea was actually to create a quick recovery time between shots.

[@BREWBETTER]

@@yasinunlu443 Not at all, the aim was to eliminate the ~4°C droop during a standard shot with a PIDd machine, to maintain a consistent accurate temperature.

[@chris9923]

Looks good. Is it more noisy when you are brewing (vs a non modified machine), or is it only noisier than standard if you have no basket / coffee (no resistance)? Thanks Also, how long do you have to leave between consecutive shots to achieve a consistent temperature between the two shots? The pid sensor i have is only going to tell me boiler temp, and not the temp in the coil. Many thanks

[@horvathpeti84]

Hi, Thank you. It's only noisier while there is no pressure in the system. During a shot it is identical to a stock machine, however every shot starts with a ramp up, until the entire system gets up to pressure. I've done most of the testing on a V1 rather than a Pro or Evo, but just now made a V2 (stainless steel boilered EU model) to V1 conversion with the coils and it's surprisingly quite. I believe it is down to the braided silicone hose between the pump and the group dumping the uneven water flow from the pump, rather than more rigid PTFE hose on V1 machines. The recovery time to pull identical shots mostly dependent on the amount of water used in the first shot and warmup time before the first shot. It could vary between a couple of minutes and 10 minutes.