New product prototype: counterflow chiller

@Elco were you recirculating?

Yes, I was. Green is kettle out, blue is kettle in.

Once ā€˜kettle inā€™ reaches the right temperature (20C around 19;07), you can start transfering to the fermentor. You donā€™t have to wait until the whole kettle is at 20C. So unless I am looking at it wrong, after 7min, you could start transferring cold enough wort to the fermentor.

@Elco what was the chilling water temp?

I believe it was 14.5C. You can see the CFC water out temperature drop when I stopped pumping the beer at 19:14.

@Elco is there is any progress on this as a product? Iā€™m in the market for a new chiller and wondering if I should wait. Thanks!

Actually, yes, I do plan to offer these. I have the 18x24 silicone tubing in stock.

I think I want to design a custom part though for fitting the inner tube to the tee at the end. I donā€™t really like the cable gland fix. I will have to discuss this with the company that makes the coils.

Perhaps 11.5m is also overkill, because the longer coil will cool better but reduce the flow rate. Reducing the length will reduce the costs too.

Thanks @Elco, keep us posted. Reducing the length sounds like a good plan. The closeness of the CFC water and wort temperatures suggests that you could go shorter (with the current flow rate). Interestingly, the CFC water out is slightly hotter for much of the graph than the wort. Iā€™ve always suspected this is the case with my plate chiller, but I donā€™t understand how that could be possible.

On a related note, the ambient tap water here in Australia can get quite warm. Iā€™m hoping to use the brewpi spark in the future to enable automatic switching from tap to chilled water (20L stored in my fridge) once the bulk of the heat is removed from the wort.

Thatā€™s the counterflow part: the water that has warmed up the most already will touch the hottest wort that just comes in. In a perfect CFC, the water output will be at the wort in temperature and the wort out will be the water in temperature.

I too am trying to get away from my plate chiller. Hereā€™s my counter-flow chiller that I based off of Elcoā€™s prototype design. I used 10m of 12 mm copper tubing inside 19 mm braided PVC tubing.

I used a 3/4 inch threaded T and went with Gardena-compatible quick connects for my chilling water connections. I then reduced the wort outlets from 3/4 inch down to 1/2 inch and used compression fittings to seal the ends of the T. I also used a second pair of compression fittings to allow for 1/2 inch connecting hardware at the ends of the wort tubing. I recently upgraded my home brewery to tri-clamp and camlock fittings, so I went with camlock outlet connectors instead of 1/2 inch hose barbs. I formed the chiller by twisting it around a corny keg but it was still a bit ā€œspringyā€, so I added the straps to keep everything tight together.

I also had some spare 3/4 inch threaded couplers, garden hose quick connects and threaded plugs. I used these to make end caps for the water connections since they like to drip any leftover water when not in use. I also have two 1/2 inch camlock dust covers on the way to keep any dust, dirt or critters out of the copper tubing when not in use. Iā€™ve yet to test it, but Iā€™m expecting impressive results.

Nice work!
I could not find compression fittings that allowed to feed through the coil all the way. What did you use for that?

What is your total length and what is the diameter of the PVC hose?
Why did you use a 3/4" tee? You seem to use reducers on most of the connections.

@Elco ,

Thanks, the PVC hose inner diameter is 19 mm. I had ordered 10 meters of hose to match the copper tubing, but as you can see I ended up cutting off about 10 - 15 centimeters on both ends fo the copper tubing. I originally planned to have a 12 mm - 1/2" copper coupler soldiered to the end of the copper tubing but a metal worker friend of mine suggested that I use something else, in case I have to take something apart in the future. Fortunately we found the compression coupler solution.

I used three of these, except the ones the chiller are 12 mm x 12 mm with 1/2" threaded ends I reduced from 3/4" - 1/2" at the ā€œTā€. I only needed the nuts with the inner compression hardware from one of the coupler to seal the ā€œTā€. At each end of the copper tubing I used only one compression nut to couple the tubing to the fitting, this freed up the other 1/2" threaded end to connect hose barbs, or in my case camlock connectors. I was able to find the couplers at a local hardware store here in Germany, in the plumbing section. If you canā€™t track them down, I could always send some your way.

I went with 3/4" since it was the closest size for my 19 mm PVC tubing, and I figured that it would allow ample water contact over the entire surface of the copper tubing. I suppose 1/2" would have worked as well, but I think it would have been a bit constricting for the water flow and it would reduce the heat transfer potential. The 19 mm PVC tubing is connected to the T with a brass threaded hose barb. I only ended up reducing on the wort outlet of the T on each end from 3/4" - 1/2". The hose quick connects are connected to the T via a 3/4" double nipple. I know that male versions of these exist, but the shop where I order most of my Stainless Steel plumbing hardware from only had 3/4" in the female fitting.

Thanks for the info.

So inside the coupling, is it one copper tube going all the way through? or 2 separate pieces? it looks like a nice solution, better than the cable glands.

No problem. Yes it is all one piece through the entire chiller.

I actually wrote to you about the cable glans that you used a few months ago. You mentioned that you ordered them through aliexpress. I picked some up, but the compression was made with a plastic fitting and was far from leak proof, it actually made quite a mess.

Iā€™m not sure if they were the same that you had. Luckily, I found the compression fittings here, and I was able to finish the project.

yep, thatā€™s what I have. Mine donā€™t leak, but can still rotate around the coil. Thatā€™s why I am looking for an alternative.

Hello Elco,
Could you provide 5-7.5 m of stainless steel coil without the fittings from the store, used to create my own counter flow chiller, since I recently had some issues with my plate chiller that I donā€™t trust to be cleaned.

How many meters would be appropriate?

BR Ken

@Elco, any plans for releasing a CFC?

Not anytime soon. Getting the silicone tubing around the coil was hell, not something we could do in larger quantities. If you want to try it yourself, I still have plenty of 18mm ID tubing.
I switched to a plate chiller, but I donā€™t like it. Things easily get stuck inside it. I now have a filter in front of it.

That doesnā€™t sound like a very attactive option then, haha. Like you, I have a plate chiller. I oxiclean it before and after use, but the amount of gunk that comes out of it in insane, even after reverse flowing heavy cleaning agent through it. I bake the chiller to ensure itā€™s safe, but having beautiful clear wort and then seeing the chiller release a blob of blackness into it is painfull.
What kind of filter do you have and do you like it?

How about this take on a CounterFlow chiller?

I plan on building one of these.