Dedicated Herms Guide, Problems And Solution Thread

[surly]

Hey all, is there a preference for a particular diameter of copper pipe for use in a heat exchange?
I have bought my self a 7.5L stockpot to use and have just installed a kettle element. That all went surprisingly smoothly. Now looking into the copper pipe.
Appropriate lengths of 1/2inch coil is pretty hard to find and anything longer is getting quite expensive. Was intending to cram in as much as possible, though my ideas of 4-5 metres might be a little ambitious.

 

[TheWiggman]

General preference is 1/2" / 12.7mm mainly because of its abundance and price.

As for what wil perform better (i.e. best ramp times) the smaller the tube Ø, the better for heat transfer in brewing situations. However with a small pump going smaller Ø will restrict the flow (as will the length) and hence will slow the overall rate of change, working against the purpose. I have a personal project to put together a spreadsheet to calculate ideal lengths and diameters based on different pump types, but this won't be quick.

There are a few designs on here that have 5m+ in their HERMS, it's not an outrageous idea but might be slight overkill.

 

[surly]

General preference is 1/2" / 12.7mm mainly because of its abundance and price.

As for what wil perform better (i.e. best ramp times) the smaller the tube Ø, the better for heat transfer in brewing situations. However with a small pump going smaller Ø will restrict the flow (as will the length) and hence will slow the overall rate of change, working against the purpose. I have a personal project to put together a spreadsheet to calculate ideal lengths and diameters based on different pump types, but this won't be quick.

There are a few designs on here that have 5m+ in their HERMS, it's not an outrageous idea but might be slight overkill.

Thanks mate.

I was thinking that length based on the length availability of copper coil. There seems to be 3m, 6m and 18m. Obviously 18m is way too long and very expensive. I was concerned that 3m might be too short, but based on price and availability it is very tempting.
If you think this will be good enough, then that makes my life easier, especially when you factor in that masters have run out of the 6m stuff..

 

[dent]

3m is heaps. Even 1.5m is enough. I've done it, works fine.

 

[idzy]

The most important factor in my opinion is the displaced water volume. The element needs to be transfering as much heat to the wort as possible. With lots of water in the pot it does this less efficiently. That's why many opt for a smaller pot and why HLT herms units generally operate not as well. It is to do with the volume of water you are heating prior to heating the wort.

There is nothing wrong with a large coil with small displaced water as the water won't hold heat for long and cause overshoot.

*I'm not a scientist.

 

[idzy]

A theoretical calculation I was doing was ratio of wort in herms coil vs water in hex. The closer these are to one another the better I would say.

 

[Beerisyummy]

A valid point is that you should keep as much space as possible around each coil. An alternative is to circulate the water over the coils

Dent is right about the lengths that will work. 3m should be plenty of compensation for any cock ups in design.
Just my opinion.

 

[surly]

Interesting info guys.
I have bought a 3m coil and will start putting this together in the next few days. Expect the volume of wort versus HEX fluid volume to be more in the HEXs favour..

 

[pk.sax]

Finally put together the hermit in the HLT. Ghetto-ish implementation atm, ideally I want a 5lt urn for the hex. C'mon eBay....

 

[Online Brewing Supplies]

Finally put together the hermit in the HLT. Ghetto-ish implementation atm, ideally I want a 5lt urn for the hex. C'mon eBay....

ImageUploadedByAussie Home Brewer1402201080.223722.jpg

ImageUploadedByAussie Home Brewer1402201098.356638.jpg

Wont work if its upside down unless the air is very hot , is this reverse herms ?
Dent will love the cable ties !
Nev

 

[pk.sax]

Heh, lots of hot air Nev, lots and lots

I had not realised what a bitch this thin stainless is to drill. One broken pilot bit and another blunted pilot bit later... I need a shed, seriously.
Step bit did the job nicely in the end though.
I do have a complaint about the hermit coil. It doesn't look half as shiny as those pics when you first brought them out!!! Lol

 

[Camo6]

That's cause when they first came out Nev couldn't take his hand off it. I can't take mine out of the hex for fear of being blinded. I love my Herm-it coil but I fear he did first.

 

[pk.sax]

Fitted ball valve to HLT/herms. Also rigged up un-intentional boil dry protection:

 

[Fat Bastard]

Some more detail of the grain bed lifting: when crushed at 1.6 with the LBP it would quote often release trapped air during mash out and especially when starting the transfer to the kettle. This would upset the bed and release grain particles to the kettle.

With the big pump, the whole bloody thing lifted to the top of the mash liquor as a single unified mass. No channelling, and only some tiny bits of grain got to the kettle. It sank as the level dropped when the fly sparge stopped and behaved normally.

At the 1.2 crush it stayed put, but channelled like a ******* and was very solid, and I suspect this is the reason for the channels.

Anyway... finally got around to doing a brew with the grain crushed at 1.4mm. I also plumbed a valve onto the pump outlet to throttle the speed.

No stuck mash with the pump throttled back about half way, but the bloody grain bed lifted again, same as before. Also the wort wasn't real clear, but its hard to tell with a porter.

However, I think I'm on the right track here, the bed didn't lift when the valve was changed to lauter, and it stayed put for a good period whilst I fiddled around with the sparge balancing. Some air seemed to come out of it, but much less than I've seen previously.

I'll try running flat out again next time and see how it goes.

 

[MastersBrewery]

That's cause when they first came out Nev couldn't take his hand off it. I can't take mine out of the hex for fear of being blinded. I love my Herm-it coil but I fear he did first.

what cocko's away and now you want to complain about sloppy seconds. h34r:

 

[fattox]

Anybody use a BCS460? I'm about to rig one up with my 2V Herms BIAB system. Trying to find the right probes is an absolute prick!

 

[Online Brewing Supplies]

Anybody use a BCS460? I'm about to rig one up with my 2V Herms BIAB system. Trying to find the right probes is an absolute prick!

I gave up on that business after contacting them twice and getting no reply. I hope their product support is better.
Nev

 

[mb-squared]

Anybody use a BCS460? I'm about to rig one up with my 2V Herms BIAB system. Trying to find the right probes is an absolute prick!

I do and have been very happy with it. I've written about it here: http://aussiehomebrewer.com/topic/79002-controlling-a-honeywell-gas-valve-with-bcs-460/

as for probes, try here or here.

Cheers,

 

[Rieewoldt]

hi guys,

not sure if this has been touched on before. I plan on using beersmith 2 when my herms build is complete.. Beersmith asks for mash tun deadspace (space under false bottom). I assume this info would be used by beersmith to adjust strike water volume to ensure that the entire strike volume is always in contact with the grain? does a herms system negate this information seeing how it would be recirculated anyhow? I suppose that the volume in contact with the grain is less when recircing (wort in lines, coil).... am i overthinking it? what does evrybody else do?

 

[QldKev]

hi guys,

not sure if this has been touched on before. I plan on using beersmith 2 when my herms build is complete.. Beersmith asks for mash tun deadspace (space under false bottom). I assume this info would be used by beersmith to adjust strike water volume to ensure that the entire strike volume is always in contact with the grain? does a herms system negate this information seeing how it would be recirculated anyhow? I suppose that the volume in contact with the grain is less when recircing (wort in lines, coil).... am i overthinking it? what does evrybody else do?

It's the volume of wort that is left behind after you have drained your runnings from the mash tun. The HERMS does not effect this.