# Herms Design



## fraser_john (9/9/09)

T-pieces are for inclusion of thermocouples/sensors at inlet and outlet of heat exchange coil. 
1/4" tube at bottom of HEX is for draining water after brew complete. 
Lid should be close fit so that any boiling of the water does not result in water splashing everywhere. 
Has 6.9cm of room at the top for inclusion of a float switch to prevent activation of heater element when water is not present or of insufficient level.
Coil has vertical entry at bottom to assist in wort draining or cleaning solution drainage.

Anyone think of any other features that should be added before I send it for a quote?


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## therook (9/9/09)

fraser_john said:


> T-pieces are for inclusion of thermocouples/sensors at inlet and outlet of heat exchange coil.
> 1/4" tube at bottom of HEX is for draining water after brew complete.
> Lid should be close fit so that any boiling of the water does not result in water splashing everywhere.
> Has 6.9cm of room at the top for inclusion of a float switch to prevent activation of heater element when water is not present or of insufficient level.
> ...




Does this mean your old system will be for sale John 


Rook


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## fraser_john (9/9/09)

therook said:


> Does this mean your old system will be for sale John
> 
> 
> Rook



On the assumption that I can get it cheap enough, the RIMS tube component certainly will be(minus the heater elements), yes.


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## chappo1970 (9/9/09)

FJ,

Perfect! Simply stunning would you be able to post up what the quote comes to please?

Cheers


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## fraser_john (9/9/09)

Chappo said:


> FJ,
> 
> Perfect! Simply stunning would you be able to post up what the quote comes to please?
> 
> Cheers



Certainly will, might get cheaper if we get more buyers? Guess that is something I will ask when I send it through to them.


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## browndog (9/9/09)

Hi FJ, I'm building something similar to this ATM using a fire extinguisher for the housing and 1/2" copper tube for the coil, the only difference is I don't have my coil entering though the bottom, it enters and exits though the sides. Looking at your measurements, I was wondering how they will get a coil that measures 115mm into the cylinder measuring 100mm? I was limited to this as it was impossible for me to get the coil in any other way.


cheers

Browndog


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## fraser_john (9/9/09)

browndog said:


> Hi FJ, I'm building something similar to this ATM using a fire extinguisher for the housing and 1/2" copper tube for the coil, the only difference is I don't have my coil entering though the bottom, it enters and exits though the sides. Looking at your measurements, I was wondering how they will get a coil that measures 115mm into the cylinder measuring 100mm? I was limited to this as it was impossible for me to get the coil in any other way.
> 
> 
> cheers
> ...



I have the coil diameter set to be 80mm outside diameter, giving 10mm either side inside the cylinder. No doubt copper would be far easier to work too, but I want mine all stainless so I can clean it with caustic.


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## browndog (9/9/09)

fraser_john said:


> I have the coil diameter set to be 80mm outside diameter, giving 10mm either side inside the cylinder. No doubt copper would be far easier to work too, but I want mine all stainless so I can clean it with caustic.



How will they join it once it is in the cylinder?


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## 3G (9/9/09)

I will take one if the price is not silly. Keen to get the HE all stainless.


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## chappo1970 (9/9/09)

browndog said:


> How will they join it once it is in the cylinder?



Chinese people with teenie weenie hands... h34r: 

I can understand the caustic thing but copper is a great conductor of temperature. That's what won me over in the end.

Cheers

Chappo


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## fraser_john (9/9/09)

They can TIG weld it from the outside once its in the cylinder (I hope) <_<


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## bigholty (9/9/09)

Have you found a heating element with a 1" NPT thread? From my experience, the smallest commonly available immersion element has a 1-1/4" BSP thread, might be worth checking this (if you haven't already). Also, you may want to consider getting them to TIG a bracket of some kind onto the unit to make mounting it easier down the track. Hope it goes well, it'll be a pearler when it's done!
Cheers, bigh.


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## fraser_john (9/9/09)

bigh said:


> Have you found a heating element with a 1" NPT thread? From my experience, the smallest commonly available immersion element has a 1-1/4" BSP thread, might be worth checking this (if you haven't already). Also, you may want to consider getting them to TIG a bracket of some kind onto the unit to make mounting it easier down the track. Hope it goes well, it'll be a pearler when it's done!
> Cheers, bigh.



All three elements I currently use are 1", not NPT though, so they are a tight fit. Plumbing Supply I note that they don't ship to Australia, but I have family send them to me. Probably other places that you can get them though.

Mounting bracket is a good idea, I'll add that to the drawing tomorrow!


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## browndog (9/9/09)

fraser_john said:


> All three elements I currently use are 1", not NPT though, so they are a tight fit. Plumbing Supply I note that they don't ship to Australia, but I have family send them to me. Probably other places that you can get them though.
> 
> Mounting bracket is a good idea, I'll add that to the drawing tomorrow!



Stokes in melbourne sell 1" BSP elements, I have 3 of them.


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## fraser_john (10/9/09)

Will totally have to revisit the design, the tightest stainlessstuff.net can coil 12.7mm stainless is 150mm, so that would make the overall diameter of the herms unit 170mm, which would also reduce the height significantly. Height is important as the electric element needs to stay submerged.

Browndog, does Stokes have a website? What is the length & wattage of your elements?


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## AndrewQLD (10/9/09)

fraser_john said:


> Will totally have to revisit the design, the tightest stainlessstuff.net can coil 12.7mm stainless is 150mm, so that would make the overall diameter of the herms unit 170mm, which would also reduce the height significantly. Height is important as the electric element needs to stay submerged.
> 
> Browndog, does Stokes have a website? What is the length & wattage of your elements?



They sell them here too elements

Andrew


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## fraser_john (10/9/09)

AndrewQLD said:


> They sell them here too elements
> 
> Andrew



Thanks Andrew!

Looks like a cylinder height of at least 400mm would cover most of the screw-in elements listed. Would add about 6cm above that for installation of a float switch and allow room for any potential boil in the HERMS cylinder.

Also, was told that just the stainless coil alone would be around US$100 including shipping! Add some fittings and the cylinder and we might be looking at US$200 for one of these units.


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## technocat (10/9/09)

fraser_john said:


> Will totally have to revisit the design, the tightest stainlessstuff.net can coil 12.7mm stainless is 150mm,



Yes I went thought this exercise with Emanuel and if you are looking at the coil tails coming off at right angles ie: through the side of the of the HE you will need some clearance around 40-50mm to fit the coil up for welding through the HE wall.


View attachment 30728
like this without the fittings on the end naturally


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## browndog (10/9/09)

fraser_john said:


> Will totally have to revisit the design, the tightest stainlessstuff.net can coil 12.7mm stainless is 150mm, so that would make the overall diameter of the herms unit 170mm, which would also reduce the height significantly. Height is important as the electric element needs to stay submerged.
> 
> Browndog, does Stokes have a website? What is the length & wattage of your elements?




www.stokes-aus.com.au they have a good pdf file to download that has all the specs of the elements they sell.


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## fraser_john (11/9/09)

After a few emails with Manu at stainlessstuff.net I have changed the design to suit his bending capabilities. The HERMS cylinder is tall enough to fit all but the very longest and highest powered elements available from places here in Australia. Fittings are now all BSP instead of NPT.


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## chappo1970 (11/9/09)

fraser_john said:


> After a few emails with Manu at stainlessstuff.net I have changed the design to suit his bending capabilities. The HERMS cylinder is tall enough to fit all but the very longest and highest powered elements available from places here in Australia. Fittings are now all BSP instead of NPT.




FJ,
If it was me I would place the coil closer to the top of the HE vessel to take advantage of the thermoclines. Just an observation and comment really other than that it's looking the bomb. Any indications of costs yet?

Chap Chap


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## fraser_john (11/9/09)

Yeah not a bad idea, I need to leave some room at the top for the float switch to control the SSR, but could raise it 50mm or so. No indication on cost yet, just sent pics off this morning.


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## chappo1970 (11/9/09)

Oh yeah forgot about your float  . Probably leave as is FJ.


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## crozdog (11/9/09)

FJ, maybe you could use an element like this one:



It would save you a bit of space.
Contact www.thermalelectric.com.au or you might be able to make one from the bendable elements available from Stokes (http://www.stokesap.com.au/Downloads/Stokes_Service_Manual_%20Sect_K.pdf).

If using a bendable element, why couldn't you wrap it around the coil? or would that risk getting the coil too hot & potentially scortching your wort?

Do you need to add a stirer to cope with the increased diameter?


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## technocat (13/9/09)

I have been looking around some time now for a suitable vessel for a herms setup for my rig and and haven't even come close until yesterday when I walked into a second hand shop in Hobart and lo and behold discovered this discarded Wormald S/steel fire extinguisher resting behind a pile of junk. A quick exchange of ten bucks and it was mine. This vessel measures 500mm x 170 and is ideal for my setup.
I will cut the height down to a round 400mm and fit a new bottom to accomodate a vertical heating element and allow access to fit the S/steel helicoil, courtesy of Stainlessstuff (Vietnam) and a thermowell for the PID controller. With my brewrig approaching the two grand mark and reaching the final stages of completion I am putting the brakes on as this is about as far as I want to go with it financially. I suppose the bottom line is, if you have the patience and the time sooner or later something on the cheap will turn up.


View attachment 30842


:icon_cheers:


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## browndog (13/9/09)

Top score there Beernut, perfect for your requirements.

cheers

Browndog


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## technocat (13/9/09)

Yeah BD sometimes you can get lucky. You don't see to many S/steel fire extinguishers around as most I have seen are painted and probably made of steel to reduce costs. Even these would do the job even if you still wanted to fit a S/steel helicoil to it, just don't look as pretty.


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## fraser_john (7/10/09)

OK, initial costing of this is US$182 including postage, so with last nights Aus$ rate, works out Aus$206 delivered, probably going to get him started on fabrication of it when I next hear from him.


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## fraser_john (8/10/09)

Fabrication is probably going to start in the next day or two and will be complete within a day, so that is pretty neat, means if I am happy with it I could have it in my grubby little hands within two weeks. 

I have asked about reduced costings for subsequent orders if others are interested.


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## raven19 (8/10/09)

FJ - I am sure you will post piccies once it arrives for us all to drool over :icon_drool2: 

Looking forward to seeing how the final product shapes up!


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## sinkas (8/10/09)

so does it c ome with a element, or just a hole for one?


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## blekk (18/10/09)

Any news on this?


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## kook (18/10/09)

That looks awesome, would be interested to see the end pricing.

Are you planning on using it purely for maintaining temperature, or do you think that you'll be able to raise the temp with it?

What plugs the drain tube? Is it threaded?


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## rwmingis (18/10/09)

fraser_john said:


> T-pieces are for inclusion of thermocouples/sensors at inlet and outlet of heat exchange coil.
> 1/4" tube at bottom of HEX is for draining water after brew complete.
> Lid should be close fit so that any boiling of the water does not result in water splashing everywhere.
> Has 6.9cm of room at the top for inclusion of a float switch to prevent activation of heater element when water is not present or of insufficient level.
> ...



Hi John,

Looks pretty good. Have you considered copper over SS for the coil? It conducts heat 20-30 times better than SS (ie smaller coil and tank), is cheaper, and easier to work with. Though, admittedly not as flash though...

Cheers,

Rob


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## fraser_john (19/10/09)

Sinkas - no it does not come with an element, only comes with the 1" BSP coupling for an element

Kook - plan on raising temp with it, with an 3000w element, should be able to ramp at about 1c/min.

Bob - had thought about copper yes, issue is that copper does not really like extreme ranges of ph such as caustic soda or acid for cleaning, so stainless is the best solution for a CIP routine.

I had contacted Manu about getting started on it after the final quote was about Aus$200 shipped. Have not heard back from him yet.


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## fraser_john (21/10/09)

Latest update.

To alleviate concern about fitting sizes and element screw in size, I am sending him a 1/2" T-piece and an element out of my RIMS tube, for me, this means no more brewing until I get it back 

BUT, it means certainty when it comes to that last nagging doubt I had about communicating thread sizes and the like.

So, once he gets them in the post, he is going to start the build and we should be right to go for delivery of the first one.


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## JonnyAnchovy (11/11/09)

Any news on this?


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## fraser_john (11/11/09)

JonnyAnchovy said:


> Any news on this?



Arrrgh, not yet, looks like either AusPost or Vietnam post has lost my sample stuff I sent!!! Still he is off to visit his version of the post office to see if they just have not delivered it.


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## JonnyAnchovy (11/11/09)

fraser_john said:


> Arrrgh, not yet, looks like either AusPost or Vietnam post has lost my sample stuff I sent!!! Still he is off to visit his version of the post office to see if they just have not delivered it.



Keep us posted - I'd be keen for a unit exactly like this!


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## sinkas (11/11/09)

JonnyAnchovy said:


> Keep us posted -



the evil irony


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## JonnyAnchovy (11/11/09)

but cruel of me. 

keep us *updated*


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## fraser_john (18/11/09)

They received my posted NPT t-piece and the electric element (1" Boss) and he found that he could actually source stainless fittings to fit these exactly, which is great news.

He posted me a video of what I sent and the fittings he found to prove they screw together properly, nice customer service there!

You can view the video , apologies if the quality sucks, but youtube would not accept it in the format he sent it to me in.

He has confirmed feasibility and cost for the unit is US$182 including shipping. At the current exchange rate that works out to be Aus$195 odd dollars. Not bad for a 6m stainless coil HERMS unit.

I'll be paying him some time this week and then he can start the build.


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## Yorg (24/11/09)

So to be clear, the element mount is BSP?
The 1/2 NPT is functionally equivalent to BSP?
I could not see your explanation for needing the T-pieces at the entry and exit??

Cheers.


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## rwmingis (24/11/09)

Hi Yorg,

Good to see you on here again. 1/2" BSP is almost the same as 1/2" NPT and they will mate. I have a 1/2" NPT filter with 1/2 BSP pipe and it seals fine. Tape will fill the gap from the difference. A 3/8" BSP fitting however, will not match a 3/8" NPT properly, it depends on the size.

Check out this site for a compatibility table. If the pitches match, it should be okay.

There's also this site for NPT to BSP adaptors.

Cheers,
Rob



Yorg said:


> So to be clear, the element mount is BSP?
> The 1/2 NPT is functionally equivalent to BSP?
> I could not see your explanation for needing the T-pieces at the entry and exit??
> 
> Cheers.


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## fraser_john (25/11/09)

Fabrication is complete:


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## technocat (25/11/09)

G'day john

Where are you mounting a temperature probe on your unit.

:icon_cheers:


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## fraser_john (25/11/09)

Beernut said:


> G'day john
> 
> Where are you mounting a temperature probe on your unit.
> 
> :icon_cheers:



The PID will be monitoring the temp of the wort as it exits the HERMS via a threaded thermocouple and a stainless t-piece.


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## QldKev (25/11/09)

Nice looking piece of equip there!. 

I would get some pickling paste onto those welds; thoses internal ones don't look like they have been done.

QldKev


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## komodo (25/11/09)

that is an attractive bit of kit!


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## technocat (25/11/09)

fraser_john said:


> The PID will be monitoring the temp of the wort as it exits the HERMS via a threaded thermocouple and a stainless t-piece.



So the PID is not monitoring the surrounding water in the cylinder. Are you using a PID for your mash temps so you know whats happening in the mash tun given there will be a temperature drop on the way through from HE to MT.

:icon_cheers:


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## fraser_john (25/11/09)

Beernut said:


> So the PID is not monitoring the surrounding water in the cylinder. Are you using a PID for your mash temps so you know whats happening in the mash tun given there will be a temperature drop on the way through from HE to MT.
> 
> :icon_cheers:



No, only monitoring wort temperature, monitoring mash temperature can result in the wort being overheated in an attempt to bring mash up to temp. This results in enzymes being denatured.


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## JonnyAnchovy (25/11/09)

Ahhh - the age old HERMS probe placement debate........


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## fraser_john (25/11/09)

JonnyAnchovy said:


> Ahhh - the age old HERMS probe placement debate........



Yes, it is an age old debate, but.....my personal experience is that with my RIMS setup, I had the probe in the mash tun and though it read correct mash temperature, almost without exception, my attenuation was outside the yeasts specifications. When checking RIMS outflow temps, they would read 2-3c above the mash tun reading and depending on placement of the probe, could be 3-5c difference between the bottom and top of the mash.

I moved the sensor three brews ago and every brew has attenuated within the specified yeast limits. I have not yet monitored mash temperature separately from the RIMS outlet yet, but probably will eventually.


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## technocat (28/11/09)

Well at last I have mine finished and wired in. Just have the plumbing to do then a test run to chart the SV's of the difference temps between the HE and the mash tun. Looking forward to better efficiencies in my mash with this setup.

View attachment 33469
View attachment 33472



Cheers


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## JonnyAnchovy (29/11/09)

fraser_john said:


> Fabrication is complete:



Has it arrived yet? Had a chance to test it?


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## NickB (29/11/09)

That is one sexy looking rig BN 


Geez, just when I think my rig is getting there, buggers like you go and post pictures like that....

Hmmm... upgrade time methinks B) 

Cheers!

:icon_offtopic: Might have to come down for a visit next time I'm heading down home to see the parents..... Where abouts in the channel are you? I own a block of land down at Randall's Bay, just up from where the shack used to be


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## technocat (29/11/09)

G'day NickB

This rig has been a year in the making spare time. Still not quite finished but close, Trying to make beer during the building stage was a bit of a trick I'll tell you. We are at Woodbridge on the Highway so you would pass us on the way to Randell's Bay. Been down that way fishing for flathead and salmon a few times. PM me if you get down this way.  

Cheers.


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## NickB (29/11/09)

Will do mate, will most likely be early next year. Spent most of my childhood holiday down at the shack, and at the rellos at Egg & Bacon Bay, plus visiting all the little known family at Cygnet.

Know where Woodbridge is, beautiful part of the world  Miss the pristine Tassie environment, but not the Tassie cold (That being said it was 37 here today and sticky.....  Wish it would rain to fill up the tanks!!)


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## fraser_john (8/12/09)

Arrived today and installed this afternoon. Ran a water test through it. Seemed OK. Couple of things left to do:

Insulate the container
Add fluid level sensor to control SSR for HERMS element so it cuts out if it runs out of fluid
Run another test using glycol as the heating fluid
 Re-tune the PID controller
Add a stirrer, the HERMS would be much more efficient if the heating fluid was agitated, maybe an old fan motor with some sort of propeller

There are some design issues that, one a combination of fabrication & design change, the other was something I just failed to communicate to Emanuel:

I asked to raise the coil in the container, then, during fabrication, the coil height was higher than anticipated, resulting in it being a bit nearer to the top than I wanted
The outlet tube has a downward slant, meaning it will not drain properly the way I have it currently set up, something I can live with
Manu dutifully supplied me with fittings for my NPT stuff, unfortunately they are a loose fit and I had to use tons of teflon and pipe/steam sealant to get them to bind. If anyone else orders, just go with BSP!

For about Aus$210, its an excellent unit and hopefully a good investment in my brewery.

Ok, picture time.


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## Stubbie (8/12/09)

fraser_john said:


> Arrived today and installed this afternoon. Ran a water test through it. Seemed OK. Couple of things left to do:
> 
> 1. Insulate the container



Sleeping bag and sisalation reflective paper h34r: 

Looking forward to the results, John.

Stubbie


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## fraser_john (8/12/09)

Sisalation paper, where do I get that?


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## kirem (8/12/09)

clark rubber have the stuff I used.


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## Yorg (9/12/09)

Don't insulate the container. 
If you are using a PID and expect it to autotune - using an insulated container - and presumably insulated mash tun and hoses - you will overshoot and never come back down. Your autotune will not work, becuase your HEX will keep adding heat into your circulating wort even powered off, since there is so much thermal mass in the water reservoir and no ability for the system to shed heat. It makes hitting target and setting the right parameters and getting the dynamics of the system right quite difficult.
Controlling temperature is easiest when there is an ability to move up to the target (heat addition) and move down to the target from above (heat loss). With responsiveness both ways, controlling the system is easier.
The only issue with not insulating is that it is less efficient, energy usage wise. Measured in cents and carbon emmissions. 
That said, insulation from the HEX to the tun should be substantial to eliminate another vairable of the differential between what is exiting the HEX and what your mash tun does.

for HEX in the HLT type systems the issues are different.

Cheers.


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## schooey (9/12/09)

:huh: Dude... you're wife is going to have kittens when she sees that dress of hers wrapped around your mash tun...


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## fraser_john (9/12/09)

schooey said:


> :huh: Dude... you're wife is going to have kittens when she sees that dress of hers wrapped around your mash tun...



LOL, that made me smile! Its actually a 4" polyester roof insulation batt that I had my wife sew up a cover for, its got a zipper and all in it so I can zip it off when I wash the tun. Very good insulation.


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## technocat (10/12/09)

Yorg said:


> Don't insulate the container.
> If you are using a PID and expect it to autotune - using an insulated container - and presumably insulated mash tun and hoses - you will overshoot and never come back down. Your autotune will not work, becuase your HEX will keep adding heat into your circulating wort even powered off, since there is so much thermal mass in the water reservoir and no ability for the system to shed heat. It makes hitting target and setting the right parameters and getting the dynamics of the system right quite difficult.
> Controlling temperature is easiest when there is an ability to move up to the target (heat addition) and move down to the target from above (heat loss). With responsiveness both ways, controlling the system is easier.
> The only issue with not insulating is that it is less efficient, energy usage wise. Measured in cents and carbon emmissions.
> ...



Yeah I endorse what you are saying here after running water trials and subsequently two brews with my new HERMS. However I have found my overshoot in the MT is only a couple of degrees so I have countered this by turning the pump off early in anticipation. I have stripped off the insulation on the inlet side of the pump and only retained it on the outlet. I am still in the process of logging the parameters of the PID so to fine tune and take away the manual control aspect. The only problem I have is my 1800 watt element in a 16L vessel is not giving me a fast enough rise time when ramping up temps. This I intend to replace with a larger output.

Cheers
BN


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## fraser_john (10/12/09)

Not sure that overshoot is going to be a problem. If the PID has been properly auto-tuned, then its logic takes into account the rate of heating, loss, errors etc. So being insulated will not be any issue at all.

Based on Yorgs concerns I decided to run a test.

I insulated the HERMS roughly with a carboy cover (cut up sleeping bag). Then I re-tuned the PID. Overshoot was 1C and it settled back to 40C within seconds. I then changed my PID to show one decimal place and overshoot was actually only 0.2C. It then settled back to be +/- 0.1C for the whole thirty minute 40C rest.

Overshoot is not an issue for a well tuned PID.


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## kirem (10/12/09)

If the PID parameters are set correctly then the heating system should not overshoot. That is one of the fundamentals behind implementing a PID algorithm into the control system.

A system that requires a loss (in this case a heat loss) to maintain control is pretty poor engineering especially with PID enhanced control implemented.

I have the heating system including heat-exchanger, hoses and mash tun all insulated and I don't get overshoot.

I use the aubins PID temperature controller Model: SYL-2352P


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## fraser_john (13/12/09)

Just finished my first mash using the new HERMS setup. Very happy with the unit. With the Auberins PID (SYL2352P) and an insulated container, it overshot by a minimal 0.2 degrees during the mash. Mas was a four step mash including the mashout step at 76c. 

Big plus for Emmanuel at Stainlessstuff.net. For Aus$210 including shipping, this is a great unit!


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## hsb (28/1/11)

Old thread - just wondered how this HEX was holding up, looks good. Any other aspects you would have changed upon reflection?
Also, what are you using to block the drain tube when it's in use?


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