How to Build a Counterflow Chiller

Here’s how to build a counterflow chiller. To up the ante, I went ahead and partook in this little DIY project this month and made myself one. I’m not going to reinvent the wheel or anything, so here are the instructions I used; they are pretty good so I am not going to be posting my step-by-step process.

Build Your Own Counterflow Chiller

The process is pretty straight forward. If you are like me, you have never soldered anything in your life, but don’t worry, it was pretty easy. I’ll admit, it wasn’t the prettiest soldering job ever done, but I was able to get all my fittings together without any leaks on the first try.

The instructions say to use a lot of lube and I’m going to only add that you should probably get the amount of lube you think is necessary and about double it. Regardless, you are probably going to have to muscle that copper tube through the hose at some point. I thought I had more than enough lube (I used soap and water), but I got about 90% of the way through the hose and things came to a grinding halt. I ended up just cutting off the left over hose and copper piping and made a slightly shorter finished product.

Another issue I came across, which is actually covered in the above instructions, but not explicitly so (and I kind of skimmed through the instructions); make sure you secure the hose over the copper TEE fitting prior to coiling it. If you don’t, you’ll quickly discover that once it is coiled it is going to be just about impossible to do.

I had a hard time finding a coil of soft copper tubing in the length of 25′. The best I could find was 20′ and 50′. I opted for the 50′ and ended up making two chillers.

Here’s my materials for two chillers (Note: Make sure you get male and female hose-ends for your second chiller)

Also, I don’t know if it’s just the St. Louis area, but I had a really hard time finding 1/2″x1/4″ copper reducers. I did end up finally finding some locally, but even they were surprised that they had 4 in stock (only need 2, again I made 2 chillers). If you are having a hard time find the reducers I was able to find some on the internet at:

They are pretty cheap here, but you’re going to get taken to the cleaners on shipping.

So that’s my take on the process. It was pretty easy and as always more fulfilling than going out an buying one, not to mention cheaper. The total cost of one of my chillers, not including the soldering supplies, was $51.95. As opposed to about $80+ according to my internet searches, several were above $100.

And, the final product (Note: I still have to secure the coil with some zip-ties):

Yeah, it’s not the prettiest thing in the world, but it is functional and in the end that is all you need.


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