On 17-11-2014 15:09, Raiford, Michael wrote:
> On 11/16/2014 10:42 AM, Stephen wrote:
>> On 16/11/2014 15:48, Thomas de Groot wrote:
>>> On 16-11-2014 15:13, Stephen wrote:
>>>> The heat is taken from the air and the hand that is holding it. You can
>>>> feel the lighter getting cold and you can hear the butane rushing into
>>>> the lighter. The sound will stop when the pressure has equalised and
>>>> the
>>>> lighter will continue to fill up.
>>>>
>>>
>>> Such a long time since I stopped smoking that I only dimly remember
>>> these things. The cold comes from the gas expanding, right? Same way as
>>> a fridge.
>>
>> Correct.
>>
>
>
> Almost, but not fully.
>
> The cold comes from the phase change from liquid to gas (It takes energy
> to evaporate the liquid, and the liquid will happily do so, because the
> equilibrium favors the gas phase (lower pressure on the cold side) If
> there is not enough pressure on the hot side (i.e. not enough coolant)
> to condense the gas to a liquid, the refrigeration is minimal to
> nonexistent.

Ah! Thank you for that correction. Phase change indeed.

>
>
> ... As for the rest of the conversation, it's fascinating; I think it's
> pressure difference that fills the lighter.
>

That's my best guess too.

Thomas

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