We all know the arguments for IC v Plate v Counter flow chiller. But some time ago FIl/Barneey /Cooky (amongst others) all built a new type of straight Counter flow chiller and named it a GOAT chiller (because it can be cleaned using a ‘GOAT’ brush). In my opinion these are the ultimate chillers. I considered for months my chill solution for my ‘Big Fat Shiny keg’ build and finally decided on a GOAT. So what advantages and disadvantages does a GOAT have?
Advantages
1. 100% inspect able
2. 100% cleanable
3. 100% demountable
4. Expandable
5. Very coolant economical – water meter and tree hugger guys will be happy
6. No threads on the cold side – can use a Blichmann inline temp gauge
7. Very easy to build – can be built without soldering (I will cover this and the cost in a later ‘how to’ post)
8. Very cheap to build
9. Can be used in single pass or recirculation systems.
10. Clean In Place (CIP)
Disadvantages
1. Can be quite large so best mounted on a rig or carrying jig.
2. Nobody really knows the ideal pipe combination and length for the chiller. Pipe: 22mm outer 15mm inner, 15mm outer 10 mm inner, 22mm outer 10 mm inner etc. and then there is turbulation of the coolant and wort. What effects does each of these have and how can they be achieved?
I’m trying to find the answer to the above. It’s costing me a fair amount in plumbing materials but hopefully I can come up with the ideal pipe combination and help people build their own Goats.
Let me first start by saying that it’s worth bearing in mind that a good chiller depends on what you are trying to achieve. Some guys are obsessed with super quick chill times and many manufacturers quote times to chill down from boiling to wort pitching in minutes for a set batch size. This is only half the story as they often fail to tell you the coolant temperature and more importantly (IMHO) the amount of coolant used (coolant flow rate). I’ve found that some manufacturers are using 22L/min coolant flow rates – mine at home is 4.9 Liters per min (particularly slow). For my application Id like my chiller to be 100% cleanable and inspectable – sorry plate guys no matter what you say you just don’t know whats in there. I’d also like to recycle my coolant by using it as my rig cleaning water with PBW (I actually use that brilliant stuff Malt Miller sells for half the price). I brew in 42 Liter batches. I don’t want to chill too quickly because my chugger pumps are so powerful they suck hops through my Copper filter and in to the FV if I set the flow too high. It takes about 10 mins for me to do a single pass transfer so my wort flows at about 4 Liters per minute. My rig vessels hold 55 Liters of water so my ideal chiller would chill 42 liters in 10 ish minutes and use no more than 55 Liters of water and the exit temp of the coolant would be as high as possible.
So what do we need to measure to compare a chiller? Obviously wort input temperature and output temperature but also coolant flow rate, coolant input temperature and crucially the amount of coolant used to achieve the desired pitching temp. One manufacture quotes a quick chill time of 6.6 mins for a 25 Liter batch but uses 145 Liters of coolant in the process OMFG !! My 12 foot immersion chiller uses 137 Liters of coolant to do the same job.
If anyone would like to add data to this thread I would be more than happy to add this to the data table I have put together. But please measure all the above parameters so we can do a like for like comparison.
In my tests so far I have measured the amount of energy (Joules) the coolant is absorbing and hence the number of Watts being sunk by each chiller (Joules per second). Its worth noting that the wort cools very quickly sat in the Copper after flame out – we must consider this as its relevant but bloody difficult to measure. If we don’t remember this then our chiller look over 100% efficient which they are not. Also to be fair to the big Duda plate chiller it monsters through the wort chilling 25 Liter batch in just 2.3 minutes so the wort sat in the kettle has less time to cool so in effect its having to work even harder.
So I have collated some data from other manufactures (at the top of my table) for reference. I have also included two plate chillers from DUDA – they have a useful table with all the info you need to help compare them thermally. The two Duda chillers I choose are based at both end of the spectrum – entry level plate chiller typically sold over here and then a behemoth 18 inch long 40 plate which would be at the very high end of a home brewers kit (if I was going for a plate Id go for this £200 well spent). I may add some more DUDA chiller data along the way.
So here is my GOAT test data base. As you can see I’ve tested 22mm outer pipe 10mm inner pipe at 4 Meters length, 8 Meters length and 8 Meters Coolant turbulated. I’ve also tested 22mm outer 15mm inner at 8 Meters length. Smooth means they have no turbulation (inserts to cause coolant swirling or indents to cause wort swirling). I’m still testing but the interesting thing is the GOATS use a minuscule amount of coolant matching the big DUDA plate. I’m going to do further tests by increasing my coolant flow rate to see how that effects stuff but also increasing further my GOAT lengths – as it seems they are scaling unbelievable well - 22mm/10mm smooth calculations. ....the 8M 22mm/10mm smooth goat is sinking 49 Kw per square meter which is 163% of the 4M version (30Kw) it shows up obviously in the amount of coolant used (47 liters v 101 Liters). I think this is really significant as the goat lengths being tested are not showing significant diminishing returns, i.e. by increasing the lengths further performance will increase, I think GOATS are the ultimate chiller – I will keep updating this thread with more results – please feel free to add comment and suggestions in our quest to find THE ULTIMATE GOAT
Here is my 8M 22mm 10mm Goat under test (you can make them as long or as short as you like):
...and im knackered and wet lol
