Dual coil chiller

I wanted to make a chiller for standard extract batches in my 5 gal. brewpot, but felt that most chillers didn't chill the center of the kettle very well, so I made this dual coil chiller with standard hardware store stuff (man the prices have gone up recently) I havn't used it yet but my H2O temp in Michigan right now is just above 40* and I ran water through the chiller from my kitchen sink at just under 2 gals. per minute, so I have no excuse to not get another batch going soon!

Looks good. Do have the inner coil connected to the outer coil for support so as not to put stress on it?

HBHoss said:

Looks good. Do have the inner coil connected to the outer coil for support so as not to put stress on it?

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Not yet, it is all pretty stiff due to the tee connectors so I might leave it, but I also might use some stainless wire to connect the coils for support.

isnt the idea behind whirlpooling the wort during cooling was to increase surface contact with the wort chiller. wont this decrease that ability though you have increased the surface contact within those area's? or are you whirlpooling via a pump?

Im not doing any whirlpooling, just sticking it in the brewpot 10 mins before knockout to sanitize it, removing the pot from the burner, placing the pot in an ice bath, and running H20 through the coils till I get 80* or so.

let us know how it works out. thx for the pics. very interesting

Check out this thread that I started not too long ago, there is one similar to yours.
This might be becoming a trend!!

https://www.homebrewtalk.com/f51/immersion-chiller-alternate-design-98181/

I went a head and modified my chiller a bit by using some copper wire to tie the thing together and strengthen it some, I also tested it in 2 1/2 gallons of boiling H2O in my brewpot and got the temp down to 80* in just under 6 minutes! No more "chill haze for me!

Any updates on this setup?
I was thinking of doing the same thing.

My immersion chiller is coiled too high so I thought of removing 1/2 and adding it as a center coil.
The outer diameter is 8". so I was thinking of coiling it at 6" maybe 4". it all depends on what I can find to shape the coil around. I would bend it as one piece though just to eliminate possible leaking/failing joints.

cool design! I am looking to make an immersion chiller soon and like the idea of a double coil chiller.

What diameter copper did you use?
What did you use for solder?

Thanks
Redbeard5289

I used 1/2 outer diameter refrigerant copper.
I used lead free solder "Silver something.." My first time working with copper and didn't have any problems.

Fittings for 3/8" fit perfectly. The 2 towers are 1/2" inner diameter copper.

water will take the path of least resistance when it gets to the t it has a choice and it will always choose the easier path so I'm afraid you will be getting flow through one of the coils at a good rate and the other not so good may be better to put them in series.

danger831 said:

water will take the path of least resistance when it gets to the t it has a choice and it will always choose the easier path so I'm afraid you will be getting flow through one of the coils at a good rate and the other not so good may be better to put them in series.

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I think you're correct Danger. This is why my coils are connected in series. The water will flow the same across the entire chiller.

water will take the path of least resistance when it gets to the t it has a choice and it will always choose the easier path so I'm afraid you will be getting flow through one of the coils at a good rate and the other not so good may be better to put them in series.

Click to expand...

I think you're correct Danger. This is why my coils are connected in series. The water will flow the same across the entire chiller.

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I don't think a series connection would be very efficient. The single coil that most people use already discharges hot water. A second coil in series would simply start with the hot water discharge from the first coil. Running your cold water into both coils simultaneously as you have would be more efficient. But Danger may have a point regarding this particular setup. The water enters the top section of the T, and runs straight through the T into one coil. The other coil path is a 90 degree turn off this main water channel. If Danger is correct, it might be better if the T had the water supply entering at the bottom and then split left and right into the two coils. Same with the discharge. I am planning to build the same and use 5/8" OD tubing (1/2" nominal pipe size) into the bottom of the T and reduce down to 3/8" OD tubing (1/4" nominal pipe size) on the two legs of the T.

danger831 said:

water will take the path of least resistance when it gets to the t it has a choice and it will always choose the easier path so I'm afraid you will be getting flow through one of the coils at a good rate and the other not so good may be better to put them in series.

Click to expand...

I'm looking to build my wort chiller here soon. I really like this concept. Obviosly series makes more sense, but my only question to follow is after a certian distance isn't the water inside the chiller equal to the temp of the wort itself thus no longer giving any additional benifit? Could using this design endup just taking more space without added benifit, or am I missing something? Still it would make one heck of a pre chiller for the eventual CFC upgrade.

Sorry, didn't see that Rgray beat me to the punch.....

rgray58 said:

it might be better if the T had the water supply entering at the bottom and then split left and right into the two coils. Same with the discharge. I am planning to build the same and use 5/8" OD tubing (1/2" nominal pipe size) into the bottom of the T and reduce down to 3/8" OD tubing (1/4" nominal pipe size) on the two legs of the T.

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I think you are right that would be more efficient.

But question, wouldn't the water pressure coming from the hose plus the resistance of the water already in the coil that is in the T-straight across from the source force enough water down the 90 degree turn? My guess would be that if you turn the water on high enough, you would get maximum flow through both coils....

What is the inner coild was of a larger diameter, that would change the resistance in that coil, is there a point where we could find equalibrium?

BrewDog760 said:

I think you are right that would be more efficient.

But question, wouldn't the water pressure coming from the hose plus the resistance of the water already in the coil that is in the T-straight across from the source force enough water down the 90 degree turn? My guess would be that if you turn the water on high enough, you would get maximum flow through both coils....

Click to expand...

If it was a closed pressurized system, definitely. (Pascal's Law combined with 15 years turning wrenches on military aircraft hydraulic systems). With an open system concerned with flow volume and not pressure, I don't know. My idea for T-fitting orientation just "seems" reasonable enough to build it that way. But the original poster is having success so who knows. My limited scientific knowledge just has me using the 5/8" garden hose into a 5/8" copper tube, then split the flow about in half into two 3/8" tubes. Again, sounds reasonable.

rgray58 that makes sense. Besides, who can have a problem with bringing wort temps down to 80 in 6 minutes? better than me. I have a traditional immersion chiller that gets me to 100 quick but beyond that, it is tough. Currently, my ground water temp is in the mid 70's. Next up, build a pre-chiller that I can drop into a bucket of icewater once I hit 100.

Cheers!

I started down this path planning to buy a 50' roll of copper and build a chiller and pre-chiller. I asked questions about the length of each (25/25, 30/20, etc.) and all answers were to steer clear of a pre-chiller as being inefficient. I started research and found quite a bit of the same sentiment on this forum and others. I found a site (lost it now) that measured a relatively minor temp drop in water temp using a pre-chiller in an icebath. Most recommendations were similar. Running 70 degree water through a pre-chiller sitting at 32 degrees might get you down in the fifties or sixties. You then have a differential of cooling water in the fifties and wort at 100. Why not just pump the 32 degree water through your wort chiller for the greater temp differential which will give you a faster heat transfer rate? My plan is to use a $18 garden pump from Harbor Freight. Sit it in a bucket and connect to my not-yet-built dual chiller. Use a garden hose to keep the bucket full and start the pump. When the wort temp drop slows down significantly, start dumping ice into the bucket. When the chiller discharge gets down to garden hose temp, divert the discharge into the bucket and turn off the garden hose. Continue dumping ice until wort temp is where I want it.

I made a dual 3/8" cooler with 1/2" feeding tees to split the coolant. My first attempt had a hop clog on my whirlpool plumbing so I have no cooling reports yet.