Brian Whatcott wrote:

On Sat, 01 Jul 2006 04:29:08 GMT, cavelamb
wrote:


Anyone out there use dry ice for refrigeration?

I want to keep the cooler cooler longer.


A couple pounds of dry ice seems like a good idea,
but how to use it?

Mix with wet ice?

Or keep separate?

Richard


The CO2 evolved from dry ice is too cold for chilling food and drinks
directly, but it can keep the water ice from melting so quickly.
This suggests a cooler within a cooler - the inner cooler giving
off CO2 gas which bubbles through a water ice mixture, which chills
the food container.

Dry ice provides a tidy explosion if its vapor has nowhere to go, and
it is not a good breathing gas - but at least it gives plenty of
warning - we are designed to pant if the CO2 proportion rises
(unlike low O2 which induces unconsciousness with no warning at all.)

You might take a look at the electric cooler boxes. Either way,
expanded polystyrene is an excellent insulation.

Brian Whatcott Altus OK

Well, I asked, didn't I.

Thanks to all for the information.

As it worked out a couple or three pounds of dry ice in one corner of the
ice chest kept the rest of the wet ice well frozen for three days. (!)

I think the wet ice is acting as insulation to protect the food stuff from
the dry ice - depending on how close stuff is to the dry stuff.

My boat is an 18 foot Capri (Catalina) so we don't have a lot of room to
play with. But with the companionway open at all there doesn't seem to be
much danger from CO2. There is just not enough dry ice in the box to make
much CO2 very rapidly (as was pointed out several times).

BUT! It really does keep the cooler cooler longer...

Thanks folks,

Richard