TOPIC:

You could end up with a very short (as in not high enough) coil, i.e. it would be low down in your wort and you'll find the top of the wort stays hot while the bottom is cool. Unless you make it in such a way that it hangs on the edge of your boiler. It wouldn't really be increasing the surface area, as it's the same surface area, just in a different configuration.

As far as I know, the commercial ones have a similar coil diameter, or at least not far off. Anyone got one they bought and can measure the internal diameter?

I have 30m of the stuff so I was thinking of doing about 10-15 loops twice and I was gonna set it up so I could hang it over the edge of the boiler so it sits high up in the Wort.

I'm just wondering if I'm missing something really obvious if I do it this way?

30m?! <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s:D --> I used 14 in my last one, and most are 10, so you're gonna have bloody tonnes of surface area with that amount. It'll be heavy though, especially when full of water.

In that case, I see no issue with a double coil, except normally you run cold in the top, and take hot from the bottom. With a double coil that might go down, then up, you might not be getting the benefit, as the water will already be hot on the way back up the second coil, so it won't be taking as much heat out of it.

That's a non-scientific description <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s:) --> But do you know what I mean?

I got it from a supplier in work for €30 but I'm aiming to use no more than 15m due to the reasons you gave.

It's just a pain that I can't get a pipe at the right diameter to use. And I've waited long enough at this stage and it's holding up my next brew. It's been a total pain waiting but I refuse to do another brew without a chiller! <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s:D -->

This weekend is the perfect time to make the chiller and do the Brew So I'm trying to make do with what I've got.

I say go with the 150mm pipe, and make a tight coil tall enough to fit your boiler. If you only use half of your 30m, you'll have enough to make another if you're not happy, or make another and sell it to another ICBer <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s:) -->

Or... make two, and couple them. Use one outside in a bucket of ice before it flows into the one in your wort so you really super charge your cooling <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s:D --> And sell it if you don't need it.