To this point, I have not yet used an immersion chiller, but am considering one. I currently place the kettle inside a tub of cold water (with hose running to replenish the cool external source as it warms, as well as to circulate). Even if I do get an immersion chiller, I may still do this, to cool from the exterior walls as well as internally in the wort.
The chillers that I am looking at purchasing are generally coiled to a 10" diameter. My boil kettle has an inside diameter of slightly less than 12", which means the chiller will be less than an inch from the kettle walls. Not much room to 'stir' it. I assume most people are using larger diameter boil kettles than I am (I brew smaller batches, generally 2.5g to 4g.)
Should I be trying to find a smaller [tighter] coil, or is this ideal for my kettle size? Or, can I stretch it and attempt to coil it a bit tighter, or is that risking compromising its structural integrity?