Convert this immersion chiller into a counterflow chiller ?

[brewman !]

I recently came to own an immersion chiller. It is 18 wraps of 3/8" tubing. I'm guessing 50 feet of tubing.

I have a plate chiller but dislike it because it is very prone to plug. I'm not a fan of immersion chillers. I'd love to have a tubing type counterflow chiller.

How difficult would it be to convert this chiller to a counterflow design ?

How hard would it be to push hose over the existing wound copper coil ?

What kind of hose would work best ? Cheap 1/2" garden hose ?

How about Aqua Joe

AJFJH50-58-PRO FiberJacket Non-Expanding Kink-Free Garden, RV, Marine and Camper Hose, Ultra-Lightweight,​

https://www.amazon.ca/Aqua-Joe-AJFJH50-58-PRO-FiberJacket-Non-Expanding/dp/B084RDJ788?th=1
Is it worth winding the copper tubing with copper wire to increase the turbulence of the cooling water ?

Thanks

 

[Broken Crow]

Easy to do, just tedious. You definitely want to unwind it to a long straight shape, and I highly recommend using a 'bending spring':
https://www.amazon.com/Armour-Line-...rds=tube+bending+spring&qid=1669904472&sr=8-7The spring will ensure you don't kink it when you're halfway through. If you try and wrap it while coiled, it will bind up.
For the tee's, I went the easiest route when I saw these in the hardware store:
https://www.amazon.com/EFIELD-REDUC...?keywords=pex+tee&qid=1669904584&sr=8-31&th=1I'm not sure which version will show up in that link, it should be the "3/4x1/2x3/4", which you'll then take a 3/8" drill bit and bore out inside the 1/2" barb to ensure the tubing will fit through properly, but still snugly before soldering.
For the garden hose, I'd recommend a simple decent one like this, with the braid layer:
https://www.homedepot.ca/product/st...0-ft-professional-grade-water-hose/10014904225/8" is a decent size and can be stretched over the 3/4" PEX easily. I made mine on a spur of the moment insomnia kick, and just went outside and took my 15 year-old hose from my garden reel. I stupidly did it all inside my house, with uncoiling beginning in the far corner of my basement, but having to leave a wide curve in it to go up the landing to my kitchen... it was living hell pulling the hose around the bend even though it had an 8-foot or so radius..and I had lubed the copper to help.
It came out ugly but marvellously functional and at about 33' (I cut some off) with my tap water coming in at 58°, I can run my boiling wort down to 68° as fast as it leaves my kettle with the cold water faucet open only a 3rd of the way. I just clamped my 1/2" silicone hose to the barb, but I do wish I'd left more copper coming out so I could use a SS compression fitting instead, and that's what I'm doing with the next one I'm making.

 

[brewman !]

"You definitely want to unwind it to a long straight shape"

Copper work hardens. My coil has probably already been straightened and rolled into its current form. It would be dicey to unroll it and re roll it.

What are the chances of sliding hose over the coil without unrolling it ?

 

[Broken Crow]

Most hoses have a tendency to stick and bind up when still coiled...you can get it to go around the first few coils but then it sticks and get progressively harder to push together, but by that time it's on far enough that taking it back off risks kinking it just as much as continuing. Using one of those springs or having the patience to fill the entire tube gaplessly with sand will keep it from kinking.. with the spring though; make sure to bend only where the spring is wrapped around it.
You could watch a few of the youtube videos of folk making them to get a 'mental-feel' for it. As to the wrapping wire around it, that'll make it even harder to get the outer hose over and in several tests I've read about, the small additional turbulance makes little to no difference. The main factor is the surface area for heat exchange, and with the length you've got, I'd say you've got that maximized. There's a science to some of it, but I've got too many shorn axons be able to recount it. I was really hoping a few others would weigh in here.

 

[Bobby_M]

There is no chance of feeding a hose over the coil. It would be better to sell that and start fresh. Though, I'm quite fond of immersion chillers for several reasons so unless you're doing 15 gallon batches I'd stick with it.