DIY dual immersion chiller design help?

[MadZack]

I'm not too satisfied with the performance of my store-bought copper tube immersion chiller, and I'm planning to build my own. After reading up on it (in this forum and elsewhere), I'm planning to do a split-dual, i.e. inner and outer coils running in parallel, since that seems the most efficient and quickest-cooling approach.

So my questions is: what would happen if I set it up so that the two coils ran in different directions? For example, running the inner clockwise, and the outer counter-clockwise? Would this affect performance at all? For better or worse? Anyone actually tried this?

I'd also be curious what folks who have built similar systems might be using to stabilize the coils and keep them separated from each other?

I'd also-also like to hear from folks about bending tubing for the final bend that hooks over the rim of the boil kettle. Should I heat up the tubing (with a propane torch or similar) before bending? Will combining torch heat and also using a bending coil ease things further?

And finally, any thoughts on SS vs. copper? Is SS much harder to work with? Are the cooling properties much worse?

Thanks in advance for any constructive/helpful thoughts you can share!

 

[adamreef]

Here is a pic of mine. It's ugly but efficient. It is four parallel tubes. I don't think that the direction of flow makes a big difference. Creating convection by keeping the chiller near the surface of the wort helps a lot.

View attachment ImageUploadedByHome Brew1479529252.087461.jpg

I stabilized the coils by soldering pieces of tubing to the sides. Heavy copper wire would work too.

Copper is much better at transferring heat and much easier to bend. I used this style bender: https://www.zoro.com/ridgid-tubing-...gclid=COnXv4j7s9ACFQlXDQodj-cMrA&gclsrc=aw.ds I strongly advise against trying to heat the tubing. You will burn yourself badly long before you get it hot enough to bend easier.