Coil length for HERMs pot and which PID?

[msilcocks]

Hi Guys,

Just building myself a Herms system and was wondering what length of coiled tubing is needed in the heat exchanger?

Also im a little lost, i have read so much on PID controllers i am pickled, can someone recommend a purchase?

THanks

 

[Aleman]

Hi Guys,

Just building myself a Herms system and was wondering what length of coiled tubing is needed in the heat exchanger?

Also im a little lost, i have read so much on PID controllers i am pickled, can someone recommend a purchase?

You Don't really need much more than a meter of tubing

As far as PIDS, I like the 1512 from Auber Instruments

 

[Vossy1]

I've also been using the Auber 1512 for many years, solid and reliable :thumb:

Just building myself a Herms system and was wondering what length of coiled tubing is needed in the heat exchanger?

There is no hard and fast rule....yet...though in theory eventually too short a pipe wouldn't give enough heat exchange for the flow rate you require. Mines a bit bigger than A's, more like 2m+ IIRC..been a long time since I measured it :lol:

 

[djcorbetto]

Ive got someone currently making me a coil for that exact pot and for the same reason but out of copper.£35.60 is what he's charging me. its 14 loops and exiting from the top, it allows space at the bottom for a burco boiler element. i'm not too sure on the length of pipe but i will find out for you

 

[Fil]

my experimental herms h/e used again just over 2m of 10mm soft copper tube coiled to fit in a 6pint vessel heated with a kettle element, when testing i measured the waterbath temp which remained within a degree of target when running well so led me to assume the coil was long enough :)

the sestos pid units are a bit cheaper than the auber models but emulate them fairly closely tho dont have all the features such as F or C display modes the sestos is C display only....
just ensure u get a ssr controller and avoid simple relay models :)

 

[prolix]

I use 8mm and just shy of 2m I believe (6 loops diameter 10cm so 60x3=180ish)
not had a problem, I use the same Pids as Vossy and Aleman.

 

[msilcocks]

Ok thanks guys for the info so my original plan of about 2.5m of tubing in a 6 litre pot should work out ok.

With regards to the auber PID controller are they only available from the USA as none popped up on a search within the UK.

Thanks

 

[Vossy1]

With regards to the auber PID controller are they only available from the USA as none popped up on a search within the UK.

The most popular are the Chinese versions and the US versions, English sourced can cost an arm and a leg I prefer to order from Auber as they're a shop, there's no potential comms problems, and should be pretty good if you have problems v Chinese E-bay sellers, though I suppose you have Paypal in your corner if you experience 'issues' with Chinese sourced stuff.

 

[dennisdk2000]

With regards to eBay, be careful. Paypal only offers any help or protecting if problems arise within 45 days of the transaction taking place. After that, even UK-based companies can be difficult to deal with!

Dennis

 

[Cyclops]

I bought 2 PIDS from ebay and they both had bits of plastic broken near the terminals at the back, they offered me about £1.20 back off them, then it went up to about £5. I put a claim in with ebay and they gave me a refund within about 10 mins.

Ebay is good if things come damaged or within the time limits but outside of that its a minefield.