Lower Cost Immersion Chiller

[Bobby_M]

With the price of copper so high, I was looking for ways to make a cheaper chiller that still had the same efficiency as the more expensive counterparts. I was using Lowes/HD prices for my comparisons and I found the following prices:

1/2" OD = $3/ft
3/8" OD = $1.60/ft
1/4" OD = $.60/ft (20 ft lengths only... any longer and it goes to $1.20/ft)

Clearly 1/4" at 20' lengths was the cheapest option but could it work as well as the larger diameters? I decided that $25 is worth the try.

I believe the biggest flaw in most immersion chiller designs is how much cross sectional area of wort is ignored or avoided. The coil is usually closer to the outside of the brewpot leaving a large cylinder of wort in the middle untouched. The coil is also tightly packed, tube to tube, which doesn't let much hot wort get in between considering the cooling power of each copper tube "radiates" around it.

My design compensates by leaving a large gap between each turn of the coil, and also doubling the coil to cover more cross sectional area. The inner coil is 5" in diameter and uses 20ft of 1/4" copper and the outer coil is about 11" in diameter and also uses 20ft of tubing. I tacked each turn of the outer coil to the section of upright tubing with a spot of lead-free solder to make the structure more rigid.
Basically the two coils join together at the input and output (also soldered together). To keep the project really cheap, I put a glob of devcon two-part metal epoxy on each end and sanded it round in order to clamp my vinyl tubing directly on without using compression fittings, tees, and reducers.

This design brought 6.5 gallons of boiling water(212dF) down to 120dF in 6 minutes using 68dF tap water through the coil. This was done without stirring the wort or disturbing it in any way.

My only issue with this build is that I didn't make the input and output runs long enough to bend over the top of the brewpot so my vinyl lines get a little close to the top edges of the pot. Then again, it's a tall, but skinny 30qt pot designed for turkey frying.

Bobby

 

[david_42]

Other than making whirlpooling harder, this design is fine. My cooler is about the same height. I decided, since the hottest wort is at the top, the cooler needed some coils up there.

 

[the_bird]

Lots prettier than mine. I used 1/4 coil, because HD sold it to me cheap when they couldn't find out the actual price. I had 50 feet, so I made a dual-coil design, splitting the water into two streams. Worked like a charm, cooled 4 gallons from boiling to ~85 degrees in about thirteen minutes, even though I can absolutely make the design more efficient. It was awesome, I could watch the cold break forming!

Yours is nice looking, though. Good job.

 

[Bobby_M]

David,
Wouldn't you remove your chiller prior to whirlpooling?

This thing should be really awesome when the tap temp goes down into the high 50's. Until that happens, I'm probably going to do an icewater bath at the same time I'm running the chiller so I can get to 70dF in less than 10 minutes. Either that, or I'm going to switch from tap to pumping icewater through the coil once I get down to 130 degrees. I already have the pump.

Bobby

 

[Todd]

This looks great, nice design and great quality. Yours is two separate coils right? Not two coils from 1 line?

I'm curious about water flow, I have a 1/2" one I built and is seems to me that the water flows so fast it is not getting very hot. Even running through boiling water I can stick my hand in the outlet flow. Would I gain any efficiency by restricting flow?

 

[Bobby_M]

Thanks Todd. Yes, the supply line splits into two different coils. I did this so both the inner and outer column of wort get exposed to cold water at the same time. Let me tell ya, the output water is extremely hot in the first 2 minutes of flow. I almost burned my hand. It sounds like your water is not spending enough time in the coil. Just don't turn the hose/faucet on full blast. Run it full until you purge all the air out of your hoses/coil then throttle it back until you feel the output water warming up. It's not that this will cool your wort any faster, but you'll use less tap water in the process.

One thing I hadn't previously considered is using my 50' run of garden hose as a pre-chiller after the inital cooling period. It won't be as efficient as copper for sure, but I can't help but think a rubbermaid tub filled with 10dF salty ice water would take my 68dF tap down to low 50's. I'll give that a try and share results when I brew later this week.

Bobby

 

[Todd]

Thanks Todd. Yes, the supply line splits into two different coils. I did this so both the inner and outer column of wort get exposed to cold water at the same time. Let me tell ya, the output water is extremely hot in the first 2 minutes of flow. I almost burned my hand. It sounds like your water is not spending enough time in the coil. Just don't turn the hose/faucet on full blast. Run it full until you purge all the air out of your hoses/coil then throttle it back until you feel the output water warming up. It's not that this will cool your wort any faster, but you'll use less tap water in the process.

One thing I hadn't previously considered is using my 50' run of garden hose as a pre-chiller after the inital cooling period. It won't be as efficient as copper for sure, but I can't help but think a rubbermaid tub filled with 10dF salty ice water would take my 68dF tap down to low 50's. I'll give that a try and share results when I brew later this week.

Bobby

I've thought about the sumberged hose idea as well. Let us know how it goes.

I'm running mine right off the hose spigot so I'm pushing a lot of water, I'll try and slow the flow down. I know it won't speed up the chill but I hate wasting all that water.

 

[the_bird]

I have a ball valve hooked up to mine so I can easily regulate the flow right from the brewpot, without having to run to the hose faucet. This allows me to fine-tune the flow to get that right balance between cooling quickly enough and not wasting water.

 

[Bobby_M]

I did something similar in that my hose sprayer has male hose thread on the output so I thread my chiller input on there. When it's time to turn it on, I lock the sprayer in the on position and use that knurled thumbscrew to regulate flow.

Bobby

 

[Bobby_M]

Just a quick followup on the real world performance of this design.

I first coiled about 30' of garden hose in a tub of salty ice water before running it into the chiller which took my 68dF tap down to about 50 with a medium flow.

Running this water though the cooler took the 6.5g of boiling wort down to 110dF in about 7 minutes. At that point the output of the chiller felt just warm to the touch so I moved the brew pot into an icy water bath to increase the continued cooling. It took an additional 8 minutes in the bath with the chiller still flowing to reach 69 dF.

This is certainly a bit of a PITA, but I'd think 15 minutes is pretty decent for a full boil. By the time I hit my next batch, the tap temp will probably be down in the low 60's or better so maybe I'll avoid the ice bath and prechiller steps. If not, the amount of trouble has me leaning towards building a counterflow.

Bobby

 

[MadWeezel]

My first chiller i made from 1/4" copper. It worked great, but one time i was making a batch and didnt have a hops bag. Big Big No no.. Plugged the 1/4 with around 1gal ran through. Lesson: always make sure you have hops baggs. My next one i built from 3/8 and cross my fingers it wont clog.
Another thing i will do is add ice & ice cream salt to the water, just gotta be careful as you could accually freeze the wort in the cooler if theres not enough flow(yes i have dont that too

 

[djamwolfe]

has anyone seen this "whirlpool chiller" concept? http://www.mrmalty.com/chiller.phpit looks real nice - as im shure a small pump is cheaper than buying a counterflow if you have a immersion chiller.

 

[Bobby_M]

My first chiller i made from 1/4" copper. It worked great, but one time i was making a batch and didnt have a hops bag. Big Big No no.. Plugged the 1/4 with around 1gal ran through. Lesson: always make sure you have hops baggs. My next one i built from 3/8 and cross my fingers it wont clog.
Another thing i will do is add ice & ice cream salt to the water, just gotta be careful as you could accually freeze the wort in the cooler if theres not enough flow(yes i have dont that too

Madweezel,
I'm not sure you realize that this thread is mostly about an immersion chiller so I'm not running wort through the 1/4" tubing. I'm running cold water through it.

Since you brought it up, I agree, I would never use 1/4" ID tubing for a counterflow style chiller.

Bobby

 

[Evan!]

Bobby,

How did you get that tubing formed up so purdy? How much was your final cost?

 

[Bobby_M]

The inner coil was formed around a piece of 4" PVC and the outter coil was formed around a bucket I had. I kept each coil tight against the previous one as I wound it around. After it's formed, you can then stretch the coil carefully to have whatever distance you like between coils. I used the upright tubes as a support and soldered each coil to it. This is really necessary because 1/4" tubing isn't rigid enough to keep that nice shape. If you don't like soldering, you could probably use a piece of 14 gauge copper wire wrapped around each coil.

The total cost was:
$25 for copper tubing
$3 for vinyl hose
$3 for two clamps
#3 for two quick disconnect hose barbs.

As I mentioned previously, in order to attach a 1/2" hose to two 1/4 tubes, I used some Devcon epoxy to form a sealing surface. This took a lot of work and would suggest you try to find a 1/4" Tee, and use reducing couplings to get up to 1/2 to clamp the hose on. It's what I actually had in mind originally, but couldn't find a reducer that went all the way down to 1/4". It could be done with brass compression fittings but would probably add another $10 to the project.

 

[ajwillys]

I realize I'm resurrecting the dead by posting in this thread but I am looking at doing the same thing (one coil inside another) with 50' of 3/8" copper.

Bobby, just wondering if you have any tips or hints now that you've had this for 2 years. I was planning on actually soldering my fittings but other than that I think I was going to do the same design as yours. Can you re-post the pic by any chance?

 

[Bobby_M]

I'd merge the two coils into a 3/4" copper tube by first soldering a cap on to the end and then carefully drilling two half inch holes in the side of the tubing so you can solder in the 3/8" tubing. If the fit is tight, the solder should hold. Thinking back to how close the hose comes to the pot, that home made collector using JB weld just doesn't seem as polished as a soldered design.

 

[ajwillys]

Wow, that does look really nice. I hope mine turns out half that nice. I was going to use a copper tee to join the two pieces into one. Any reason why that's not a good idea?

 

[Bobby_M]

The TEE will work just fine but you probably want to go with a 1/2" Tee and reduce down to your 1/4" nominal. If you go with an all 1/4" tee, the input is going to be restricted.

 

[ajwillys]

The TEE will work just fine but you probably want to go with a 1/2" Tee and reduce down to your 1/4" nominal. If you go with an all 1/4" tee, the input is going to be restricted.

Actually, you read my mind. I was planning on using 1/2" or even 3/4" rigid pipe and fittings to connect the garden hose, tee, and a couple elbows and then drop down to the 1/4" nominal as it transitions to the soft copper.

I really like how you used the vertical tube of one coil to rigidize the other coil. I was going to use copper wire, but I think I like that better.

 

[Ecnerwal]

I have a typical chiller (one coil, full height of pot) and my observation is that it tends to stratify the wort - the bottom gets cold, the top stays hot, but you don't want to stir too much and get HSA. When I get to mark II, I'm planning to make a flat disk coil that is suspended in the top of of the pot. This should help set up convection currents to cool the whole pot more evenly, as the cooled wort slides down the outside of the pot, and the hotter wort rises up the center to hit the coil.

 

[EvilTOJ]

ecnerwal, HSA is a persisant homebrewer myth. Unless you're making multibarrel batches and storing your beer for months, we never need to worry about HSA. That said, I stir the unholy crap out of the wort as it cools and it works fine.

 

[Ecnerwal]

On the one hand, I make 5-6 gallon batches. On the other, I store at least some of each batch for years - it's never gotten worse, and it often gets better. The only batch where a long time was not a good thing was the Procrastination Porter (named after the fact) that sat in tertiary for about 4 years before getting bottled. Don't do that, unless it's a mead - and perhaps not even then. Once in bottles, time is only a good thing, IME.

On the third hand, I'm probably 5-10 years out of date on what the present voodoo in homebrew is, as I've had no time for it, but not quite enough "no time for it" to dump my equipment and get out of the hobby - so I'm here poking my nose in as a step on the road to cleaning my kitchen and boiling up a batch to fill my fermenter (and get that dang carboy of mead into bottles).

I'll stick with my out of date persistent myth for now, it's not causing me any problems.

 

[SILVER13ACK]

I have a typical chiller (one coil, full height of pot) and my observation is that it tends to stratify the wort - the bottom gets cold, the top stays hot, but you don't want to stir too much and get HSA. When I get to mark II, I'm planning to make a flat disk coil that is suspended in the top of of the pot. This should help set up convection currents to cool the whole pot more evenly, as the cooled wort slides down the outside of the pot, and the hotter wort rises up the center to hit the coil.

you're referring to a planispiral chiller. I've seen that design come up before in homebrew discussions, but it's been a long time.

 

[Bobby_M]

Just keep the wort whirlpooling and you don't have to worry about stratification. The key is getting as much cooling surface area as possible and putting a small coil up at the surface of the wort isn't not going to do that.