The way I see it, hot wort sits at the top, so you want the coolest water hitting the top of the coil to get the most cooling action. At least that's been my experience. It probably doesn't make a huge difference with a single coil. Your mileage may vary...
As for the filling action, it's under pressure, so it's gonna flow anyway. You could say if you connect the input to the top of the coil, it pours in under gravity, not pushing up from the bottom. In reality, either way it has to be pushed out at some point unless you have the coil outlet coming out of the base of your boiler. <!-- s:) --><img src="{SMILIES_PATH}/icon_smile.gif" alt="

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Anyway, Palmer agrees with me and says in at the top[/url:3q039y9m]. That could have saved me a lot of typing <!-- s:D --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="

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