I just watched the WLL on the new 500 with PID and they stated that it doesn't need a cooling flush. Is this possible? How would the steaming power be if it was setup not to need a cooling flush?

Thanks

Randy

I saw this. They said something about 'fine tuning' of the E61 for the PID, etc but they never went into detail as to what that meant.

The guy who sold me my non-PID 500 also told me they didn't need cooling flushes. So....

I think the only want to tell if that is possible on the PID'd 500 is to install a group thermometer or the scace and see how the machine operates at long idle vs short idle.

I thought the nature of HX and e61 meant you'd always need a cooling flush.... But again.. I'm too new to know.

If you watch this video:

http://www.youtube.com/watch?v=pVrdQ5s0pNY

you will notice that the term "cooling flush" is avoided. An idling HX machine develops a thermal difference between the HX (hot) and the grouphead (cool). The HX flush serves to equalize this difference. I can imagine that a PID keeps a rock solid temperature in the boiler when the machine is idling instead of going through these on/off heating cycles. When you start an extraction however, the machine's dynamics cause a disturbance on this steady-state differential, PID or not. The HX flush Combined with the grouphead's thermal mass evens out this disturbance before you start the extraction. David Schomer explained it as "tricking the machine into thinking it is being used". With the thermosyphon tuned for home-use using flow restrictors and the like, the PID offers one more degree of freedom to the barista that will affect the machine's thermal behavior, but I tend to be skeptical of the thought that it delivers a noticeably more steady brew temperature without the infamous "cooling flush".

ben8jam wrote:The guy who sold me my non-PID 500 also told me they didn't need cooling flushes. So....

I think the only want to tell if that is possible on the PID'd 500 is to install a group thermometer or the scace and see how the machine operates at long idle vs short idle.

I thought the nature of HX and e61 meant you'd always need a cooling flush.... But again.. I'm too new to know.

I just rewatched the video and I think Marc needs to be more clear. What I think he is saying is that when using the machine back to back you don't need cooling flushes (like a 'dragon' machine or a PSTAT set very high). The PID is set to 252 degrees so it has to have some level of flash boiling as even the mass of the E61 can't fully bring that down to 200 degrees at the pull of a lever. If it can, I'll be shocked as this machine would seriously be putting DB machines to the test at this price range.

I can't wait for the first HBer to get one to see if it's just marketing or if it legitimately is more temperature stable than its PSTAT brethren.

I need to get an Eric's Thermometer I suppose for mine to see just how stable mine is.

I need to get an Eric's Thermometer I suppose for mine to see just how stable mine is.

Sounds like a really good plan to me

DeGaulle wrote:If you watch this video:

http://www.youtube.com/watch?v=pVrdQ5s0pNY

you will notice that the term "cooling flush" is avoided. An idling HX machine develops a thermal difference between the HX (hot) and the grouphead (cool). The HX flush serves to equalize this difference. I can imagine that a PID keeps a rock solid temperature in the boiler when the machine is idling instead of going through these on/off heating cycles. When you start an extraction however, the machine's dynamics cause a disturbance on this steady-state differential, PID or not. The HX flush Combined with the grouphead's thermal mass evens out this disturbance before you start the extraction. David Schomer explained it as "tricking the machine into thinking it is being used". With the thermosyphon tuned for home-use using flow restrictors and the like, the PID offers one more degree of freedom to the barista that will affect the machine's thermal behavior, but I tend to be skeptical of the thought that it delivers a noticeably more steady brew temperature without the infamous "cooling flush".

I have watched that video and though it is very well made, the amount of flushing did turn me off to an HX in general. I hope the new 500 requires quite a bit less water.
The local cafe has a Famea machine that they don't flush ahead of time and their drinks turn out very good so maybe an HX flush is overrated?


Randy

slipchuck wrote:I just watched the WLL on the new 500 with PID and they stated that it doesn't need a cooling flush. Is this possible? How would the steaming power be if it was setup not to need a cooling flush?

Yes, it is possible. A well tuned HX does eliminate the need for cooling flush. The PID is not the key (nor the need to turn down the pressurestat setting), but the combination of thermosiphon & hx tuning. The mechanism seems to be via regulating the heat flow from the thermosiphon to the group heat (by a flow restrictor), resulting a cooler group (hot water+cooler group = brew temp, just like a lever machine, or maybe have a smaller less efficient hx and draw water from the cooler thermosiphon leg - my theory at this stage but the use of flow restrictor is key/fact).

It appears Profitec has nailed it too from the WLL video. If you do a short flush, it seems to be a 'heating flush' instead (see the last shot).

Originally posted here:
Profitec Pro 500 cooling flush stabilization



I've gotten an official Scace since and verified the accuracy of my DIY thermofilter so it's pretty accurate.

erics wrote:Sounds like a really good plan to me

Agreed! Quick question for you: Does installing it do any permanent 'damage' to the group? In other words, if I want to 100% uninstall it, can you without there being any trace it was installed? I looked at the diagram and it looks like you have a piece that lets you partially uninstall as well as fully uninstall. I just want to confirm. Thanks!

Absolutely, you can return to "normal" in about 3 minutes.