Immersion Chiller - brass fittings or hose clamps?

I am building an immersion chiller, which I bought parts for this evening. I bought ~$20 worth of brass fittings, two each of 1/2" compression to 1/2" pipe thread, and 1/2" hose connectors. I was comparing my price at the hardware store to what was available from my LHBS, so I called up my LHBS to ask about the immersion chillers they had for sale (specifically, the length and diameter of the tubing). The guy I talked to seemed to think that compression fittings were overkill, and that I should consider hose clamps and vinyl tubing instead. So who has built one, and would you recommend hose clamps or fittings?

I'll tell you that the main reason I chose compression fittings is because my buddy's immersion chiller sprung a leak into our wort last time we brewed. The LHBS rep dismissed this as a "loose hose clamp," but a brass fitting will never get loose, no?

Also, does anyone have any advice on using 3/8" tubing vs. 1/2"? I would expect the greater fluid flow of 1/2" to be more efficient at cooling, but I would be able to afford more surface area of 3/8" tubing. Thoughts?

Some more positive connection to the tubing is better than hose clamps over vinyl. The vinyl/pvc tubing gets soft when hot so the clamp bites into it more every time you tighten it. The cleanest connection I've found is to use Garden Hose to 5/8" hose barb fittings. You can slightly drill out the inside of these barbs to 1/2" and solder them onto 1/2" copper tubing. If this is more DIY than you were hoping, I agree compression fittings are the next best thing. One other method is to put a slight flare on the end of the copper tubing if you have to clamp the vinyl tubing on directly.

Yes, I think soldering is a bit more DIY than I was hoping for. I don't think I have the tools, and I definitely don't have the knowledge/experience to do any soldering.

So it sounds like you'd endorse the fittings over tubing? I haven't priced it, but I do expect that the tubing and garden hose fittings would not be an insignificant expense. I'd be trading my $20 of fittings for, what? $5-10 of other materials?

What do you think about the copper tubing size? What size is your chiller?

Thanks for your help.

For 5 gallon batches, you can't go wrong with 50' x 3/8" OD copper. I'd step up to 1/2" OD for up to 10 gallon batches.

I have compression fittings on my 3/8 inch chiller and I'm thinking about taking them off because the hole in them is only about 1/2 the internal diameter of the tubing. I'm sure that restriction is limiting the flow and cooling ability of my chiller. I don't want to use tubing with clamps, so maybe soldering something on like Bobby suggests is the only solution for me. Soldering isn't that hard to learn, particularly if you don't care about the joint looking real pretty. All you need is a propane torch and a solder kit with solder, flux, and sandpaper which can be purchased at most any hardware store. Use lead free solder if you expect the solder joint to contact your wort, such as if you someday want to convert your chiller to a HERMS coil.

Bobby_M said:

For 5 gallon batches, you can't go wrong with 50' x 3/8" OD copper. I'd step up to 1/2" OD for up to 10 gallon batches.

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Oh boy, so my 20 feet of 1/2" OD is wholly undersized then? The hardware store I went to only had up to 25 foot lengths of 3/8" OD and 20 foot lengths of 1/2" OD. I'd rather not use a union; I'll check Lowes tomorrow for a longer tube.

redblacktree said:

I'll tell you that the main reason I chose compression fittings is because my buddy's immersion chiller sprung a leak into our wart last time we brewed. The LHBS rep dismissed this as a "loose hose clamp," but a brass fitting will never get loose, no?

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I used compression fittings on my DIY chiller, but the other thing that I did that I think is more important to preventing the problem you described is to bend your tubing so that the connections are not over the kettle, and the tubing slopes down away from the kettle, so that slow leaks (the kind you'll likely get) will drip and run down the tubing away from the kettle. That way, even if your compression fittings do happen to spring a leak, it won't run into your kettle.

redblacktree said:

Oh boy, so my 20 feet of 1/2" OD is wholly undersized then? The hardware store I went to only had up to 25 foot lengths of 3/8" OD and 20 foot lengths of 1/2" OD. I'd rather not use a union; I'll check Lowes tomorrow for a longer tube.

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Don't shy away from calling a real dedicated plumbing supply shop either. They move a lot of volume with local HVAC guys and the pricing shouldn't be too far off.

One reason I'd say 20' is too short is that a good 3-4 feet of it is already dedicated to getting the tubing into and out of the pot.

This was my origional design Just clamped to piping.





I had exactly the same leakage occur that you talked about in the OP. You couldn't tighten the hose clamp enough.

You heat the piping and it expands crushing it a little then run cold water through it which shrinks it then it leaks all over.

after that first mess mine got rebilt to what you see below



That coil has since been handed down to a friend though.

DeafSmith said:

I have compression fittings on my 3/8 inch chiller and I'm thinking about taking them off because the hole in them is only about 1/2 the internal diameter of the tubing. I'm sure that restriction is limiting the flow and cooling ability of my chiller.

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I have seen two different kinds of compression fittings, but I am not a plumber, so I may just be confused. The kind I bought is pictured below. I don't think that it decreases the diameter of my tubing at all. (or much — I used these kinds of fittings on my MLT, and the flow seems just fine)



I found 50' tubing at my local Lowes, so I'll be returning the 20' length. It was not cheap, $60, but I got the 1/2" OD. I got a 10 gallon kettle for Christmas, so I may be doing somewhat larger than 5 gallon batches at some point, and the difference in the price of the tubing was only $10, between the 3/8" and 1/2".