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Anyones Giotto & other HX Modifications

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  • #31
    Re: Anyones Giotto & other HX Modifications

    Re: the Sirai p/stat Luca....

    I think its gained a reputation for "desirability" because of its general open design and solidity that, in turn, lends itself to simple ongoing maintenance. Its design though, does not lend itself to producing a tight dead-band or low hysteresis; if this is considered important...

    Im with you as it happens, currently own one machine with a Sirai and the other fitted with a Mater XP700.... The Mater exhibits excellent control of the Boiler pressure with a hysteresis of less than 0.1 Bar and a resulting temperature differential envelope in the Boiler of roughly 1.5C. An excellent result in any terms.... 8-)

    As you touched on elsewhere, a low hysteresis p/stat in combination with a suitable SSR to switch the actual heating element(s) current, would be a very reliable and almost maintenance free proposition. Coupled with relative simplicity as a retrofit, its something worth considering too.

    Mal.

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    • #32
      Re: Anyones Giotto & other HX Modifications

      Originally posted by 55787C707D110 link=1257849256/24#24 date=1258276487
      I appreciate what youre saying Denis but so long as the Boiler only is insulated, there will be no temperature increase of the Thermosyphon Flow as the Boiler Water Temp will not be altered, just become a lot more stable.
      something I havent seen any mention of, is the effect that insulating the boiler will have on the temperature of water in the tank, especially when its left idling for several hours...
      It seems to me that a lower ambient temperature inside the machine = lower water temp in the tank = lower shot temps. would that be right?

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      • #33
        Re: Anyones Giotto & other HX Modifications

        Originally posted by 507C7C637661252A40130 link=1257849256/31#31 date=1266210478
        something I havent seen any mention of, is the effect that insulating the boiler will have on the temperature of water in the tank, especially when its left idling for several hours...
        It seems to me that a lower ambient temperature inside the machine = lower water temp in the tank = lower shot temps.would that be right?
        I was thinking you were wrong.....then i had better think.....

        Im no expert.....but, the temp in the boiler will remain constant regardless of what insulation is packed around the outside of the boiler, all it will alter is the cycle time to keep the water at temp/keep pressure, it will loose less heat there fore less requirement to activate the boiler...

        But if the water that is fed into the HX from the water tank is cooler due to the boiler being insulated....say 22C,it then passes through the HX, out the other side(prior to the e61) at eg 95C. My understanding would be the same relative with warmer water.....30C in, 103C out........

        Now this is where my brain/knowledge dies ;D does the e-61 deal with this well?

        Please someone correct me if im wrong.... and i probably am ;DI would imagine the temp of the water entering the HX would have any impact on what is passed through the grouphead.(unless the E-61 stabilises it well )

        My head hurts ;D

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        • #34
          Re: Anyones Giotto & other HX Modifications

          I have no theory for this--like WSully my head starts to hurt when all the variables come home to roost.

          On a practical level I havent noticed cold shots since I insulated my boiler, but then I did add some insulation to the casing of the machine as well.

          I do know that the tank water can get pretty warm after the machine has been on for a few hours.

          Greg

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          • #35
            Re: Anyones Giotto & other HX Modifications

            Originally posted by 74415654645C415E525F57330 link=1257849256/33#33 date=1266222214
            I have no theory for this--like WSully my head starts to hurt when all the variables come home to roost.

            On a practical level I havent noticed cold shots since I insulated my boiler, but then I did add some insulation to the casing of the machine as well.

            I do know that the tank water can get pretty warm after the machine has been on for a few hours.

            Greg
            YEp.. Too many variables and ASSUMPTIONS.

            Boiler- Insulated. Stops heat loss.. Tis all and thus is reflected in the cycle times etc.

            As to the E-61 and other systems... Insulating the neck and other components can be an issue.  Many have already done the maths and calculated the heat losses / transfers etc for a given boiler temp.

            YEP: Too many variables and ASSUMPTIONS.

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            • #36
              Re: Anyones Giotto & other HX Modifications

              The only evidence I have found re: the effects of ambient temperature relative to Brew Water temperature, is that rises in supply water temperature necessitates a slightly longer Cooling Flush Volume than when the supply water temperature goes the other way.

              Once the Brew Water Temperature is stable, that is where it stays until the machine is left idle once more. The net effect seems to be that higher ambient temperatures equate to drawing less heat from the HX than cooler temperatures. Only one way to identify this for yourself and that is to carry out your own experiments with your setup....

              Mal.

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              • #37
                Re: Anyones Giotto & other HX Modifications

                Originally posted by 7D50545855390 link=1257849256/35#35 date=1266225873
                Only one way to identify this for yourself and that is to carry out your own experiments with your setup...
                I missed the post today - had a note that a delivery is waiting to pick up at the post office - I expect its my E61 digital thermometer adapter from Eric Svendson. Ill do some experiments with "warm" tank water vs fresh "cool" water - should be close to the difference an insulated tank would make...

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                • #38
                  Re: Anyones Giotto & other HX Modifications

                  Originally posted by 6A4646594C5B1F107A290 link=1257849256/36#36 date=1266228287
                  Ill do some experiments with "warm" tank water vs fresh "cool" water
                  Really looking forward to seeing the results cooper69s, ill chuck a notification on this thread

                  cheers mate

                  Comment


                  • #39
                    Re: Anyones Giotto & other HX Modifications

                    Agreed--I too will keep an eye out for the results. Id love to know about the input/output through a E-61.

                    As i mentioned in another thread, my house hot water is an HX (I guess its actually closer to a thermoblock : ), and the output water varies in temperature almost as much as the input water temperature varies throughout the year.

                    Greg

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                    • #40
                      Re: Anyones Giotto & other HX Modifications

                      You guys do realise that you can do the test yourselves, right?

                      If you have one of Andys thermo-logging DMMs, all you need is a bead t/c instead of the probe unit. Charge the basket in your normal fashion as if intending to pull a shot, and then sit the bead of the t/c about half-way between the centre and the circumference of the basket, then carefully lock in to the group.

                      The insulation on these probes is very tough and will withstand the rigours of bending around the lip of the basket/Group without any problems. Plug the t/c connectors into the DMM, turn on, set up for temperature and then start experimenting. You can even use the thermo-logging software if you want to record the information for posterity.

                      Since youre not going to drink the results of the pour, theres no need to keep recharging the basket since youre only looking to control the water flow-rate so that you end up with real-world results rather than free pour data which is not representative.

                      Ive used this method heaps of times using the same bead t/c and it is still going strong. So, what are you waiting for?

                      Mal.

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                      • #41
                        Re: Anyones Giotto & other HX Modifications

                        I havent started with any mods yet. The first will be to insulate the boiler. I have the material and hope to get to work on the weekend. Any tips?

                        Comment


                        • #42
                          Re: Anyones Giotto & other HX Modifications

                          Originally posted by 7140544D58151115210 link=1257849256/40#40 date=1266382887
                          I havent started with any mods yet.  The first will be to insulate the boiler.  I have the material and hope to get to work on the weekend.  Any tips?  
                          Yes, insulate something else instead. Im at a loss as to understand why you would bother doing this and what you hope to achieve. :-?

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                          • #43
                            Re: Anyones Giotto & other HX Modifications

                            Isnt the decreased cycle time enough den? water in reserviour cooler, greg did it here
                            I would have thought it was a good idea, why do you think not? curious :-/

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                            • #44
                              Re: Anyones Giotto & other HX Modifications

                              I just think there are better things to do, like...get a pet.

                              Its not like I feel the need to put ice blocks in there to cool the water down on a hot day. I honestly dont think a few degrees difference in the reservoir will make any significant difference to what ends up in the cup. The flip side is that the cup warming tray will be cooler, so you either pre-heat the cups with hot water, which more than negates the cost effectiveness of cycle times, or you end up with a not so great tasting cup of coffee. If there is an argument that fewer cycle times will increase life span, then an argument must also exist that the longer cool down will shorten the life span.

                              One of the tweaks shown above has some foil insulation on the case and not too far away from electrical components. If it were to fall over it could blow the thermostat or worse still, electrify the whole chassis, and AM will tell you what will happen then. In addition, the boiler insulation appears to be attached with strands of wire which is again too close to electrical wiring for my liking.

                              I think a very good understanding of what and why you would make these types of alteration needs to be considered in conjunction with why the manufacturer didnt do it in the first place. One also needs to have the technical aptitude, and so far in this thread, I havent read anything that reassures me that this in play.

                              Much better idea would be to take a wander around the house, and see how many things are plugged in, sucking up power, that dont need to be on standby. And as I said earlier, I think it is far better to get a pet. They will add years to your life, not take them away.


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                              • #45
                                Re: Anyones Giotto & other HX Modifications

                                Originally posted by 537279797E64170 link=1257849256/43#43 date=1266390964
                                I just think there are better things to do, like...get a pet.

                                Its not like I feel the need to put ice blocks in there to cool the water down on a hot day.  I honestly dont think a few degrees difference in the reservoir will make any significant difference to what ends up in the cup.  The flip side is that the cup warming tray will be cooler, so you either pre-heat the cups with hot water, which more than negates the cost effectiveness of cycle times, or you end up with a not so great tasting cup of coffee.  If there is an argument that fewer cycle times will increase life span, then an argument must also exist that the longer cool down will shorten the life span.

                                One of the tweaks shown above has some foil insulation on the case and not too far away from electrical components.  If it were to fall over it could blow the thermostat or worse still, electrify the whole chassis, and AM will tell you what will happen then.  In addition, the boiler insulation appears to be attached with strands of wire which is again too close to electrical wiring for my liking.

                                I think a very good understanding of what and why you would make these types of alteration needs to be considered in conjunction with why the manufacturer didnt do it in the first place.  One also needs to have the technical aptitude, and so far in this thread, I havent read anything that reassures me that this in play.

                                Much better idea would be to take a wander around the house, and see how many things are plugged in, sucking up power, that dont need to be on standby.  And as I said earlier, I think it is far better to get a pet.  They will add years to your life, not take them away.

                                Fantastic answer Den.......as per usual

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