Herms coil

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In theory yes, but in practice not so much. A HERMS coil works best when it's controlling a small volume of water because the temperature changes much more quickly and an immersion chiller would need a large kettle to fit. I used a coil inside a kettle which held only a couple of litres at most.
 
Hi!
It appears that most HERMS coils are fitted inside the HLT, which is being heated to provide sparge water, therefore the energy expended to heat the water is also being used to keep the mash at the set temperature. There only needs to be one heat source, so to speak.
It has occurred to me that a cooling coil could be used as part of a HERMS setup if the HLT was controlled by a PID monitoring the wort temperature.
I am much taken by the idea of a kettle HERMS - ingenious!
There are posts somewhere about using a rice cooker as the basis of a HERMS setup.

tea kettle herms.jpg
 
If you're willing to put a bit of effort into the layout then yes. As "strange-steve" says Herms coils in a large volume HLT are very slow to make temperature changes, but I was never convinced by the small volume "HLT" argument and didn't want a coil for HERMS and a coil for cooling - I just wanted one coil for both.

HERMS coils in large volume HLTs might be slow, but they also maintain very stable mash temperatures.

My first effort (which gave very fast temperature changes but not fast, or predictable, enough for my liking) put a RIMS heater in series with the HERMS coil just for temperature step-ups.

My second effort (work in progress) takes a measured amount of water out of the HLT and heats it up "off-line" so that when it's added back to the HLT the temperature in the HLT ramps up very quickly.

If you do use a dual purpose HERMS/Cooler coil it is vital to be able to sanitise the coil between the two jobs.
 
... It has occurred to me that a cooling coil could be used as part of a HERMS setup if the HLT was controlled by a PID monitoring the wort temperature. ...
It is tricky (impossible?) to get reliable temperature changes from directly monitoring the porridge that is a mash. Better to get the temperature of the mash right then continuously recirculate through a HERMS coil in a PID controlled water bath (HLT?).


(EDIT: You might mean monitoring the temperature of the wort just before it enters the HERMS coil? But this still gives the PID a limited view of the mash temperature as a whole and will probably result in "erratic" temperature control.)

(EDIT2: Unless the water bath (HLT?) is agitated to keep temperature uniform, that could result in erratic temperature control too. Mine is. I did say if "willing to put a bit of effort into the layout".)
 
Was just a thaught thats all. I think il just stick to what im using for now. Im getting a pump so thaught a herms coil i can take out would be pretty good
 
Hi peebee,
I have a RIMS setup based on an ACE mash tun/boiler. The temperature sensor is situated just after the ball valve and measures the temperature of the wort as it leaves the ACE. I realise that there will be temperature differences throughout different levels of the mash, but the recirculation should minimise these. I didn't fancy a HERMS setup simply because RIMS was easier to build, for me, at least.
I have a very hi-tech agitation device for my HLT - it's called a spoon :grin:.
 
Was just a thaught thats all. I think il just stick to what im using for now. Im getting a pump so thaught a herms coil i can take out would be pretty good
 
... The temperature sensor is situated just after the ball valve and measures the temperature of the wort as it leaves the ACE. ...
Hi Bigcol. When I was building the brewery I was convinced the PID temperature probe had to be after the RIMS heater so temperature wouldn't overshoot. Only now do I realise temperature is unlikely to overshoot by much (unless you've got a very powerful RIMS heater; mine's just 2.4kW) and putting the probe on the outlet leads to torturously slow convergence with the selected temperature. So what I do is dial in an overshoot of 1-2C - sort of destroying the argument for putting the probe on the RIMS outlet in the first place.

Still, permanently plumbed in system so can't easily change it now. Instead I'm supporting the HLT (and therefore HERMS) with a second "offline" HLT. I've only just got used to the extravagance of one HLT (didn't we always just reach for a kettle, or pan on the cooker?), now I'm busy building a second!

As for agitating the HLT. I don't really have a coil in the HLT. The "coil" is jacketed and the jacket fed by the HLT (easily switched to mains cold for cooling). Pumping the water in and out of the HLT does the agitating.
 

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