Immersion Chiller design

[Scotty]

Having moved house and converted to outdoor gas brewing, I am wanting to simplify my brewing by removing the need for pumps/pipework etc for my CFC.

I know the pro's and con's of different chillers but what I would like to know is, how should I design a decent IC?

Two options.....

1. Microbore wrapped around a corny
2. 15mm pipe and 90 degree bends

I guess my question is, is it better for the water to flow in a smooth manner in the microbore, or allowing the water to become turbulant when travelling around 90 degree bends?

[boingy]

Definitely microbore, and as much as you can muster. Arrange it so you get a decent coverage across the top half of the wort.

Turbulent flow is better in theory but in practice the limiting factor is the lack of circulation or agitation in the wort, hence the reason many folk stir the wort as it cools.

I've recently gone the other way. My most recent brew was the first to use my new plate chiller rather than the IC. I've just got enough height difference to make it work without a wort pump.

[Scotty]

Cheers boingy.

sadly I don't have the ability to use gravity as a method.

For what it's going to cost, I could potentially buy a new wort pump (if my current one breaks) and use my CFC.

[boingy]

I may well need to add a pump because I am planning to build a home made hopback. I don't think I have enough height to gravity feed through that.

With an IC it's surface area that you need. Microbore packs more surface area into a smaller space. But as you say, it's not cheap.

[gregorach]

I guess my question is, is it better for the water to flow in a smooth manner in the microbore, or allowing the water to become turbulant when travelling around 90 degree bends?

At typical flow rates, you'll have turbulent flow in the microbore as well.

[BlakenhallBrewer]

As Boingy says it's surface area that's needed for an IC

Here's some pictures of my twin coil IC



It's made from 10M of 10mm microbore which i wrapped round a couple of sweet jars



With the coils inside each other I connected the top of the inner to the bottom of the outer and vice versa



Works well for me

[Fil]

I did a double coil in one by first wrapping round a smaller vessel (stainless steel cutlery holder) and then inserting this coil inside the paint tin i used to wrap the outside coil.. all in one no welds other than attaching the 15mm in and out pipes just make sure you have a nice round bit of microbore to weld onto the 10-15mm converter as coiling will flatten the tube a bit. if you coil to the end of the tube it will all be slightly flattened.

another thing to bear in mind is the size of your boiler, you want a coil small enough to allow you to get in with a paddle and give a good stir to keep hot liquor in contact with the coil. you can stir with the coil but this will put pressure on the welds.

last brew of 20l final volume in the fermenter took less than 15mins to chill below 27oC (tho i was on the patio n it was a chilly day)